Update 3: Extremely important note to check before getting your bearing(s) replaced: my bearing noise started coming back within a few weeks and the culprit is almost undoubtedly old strut/springs. Therefore, I will be replacing the front strut assemblies in addition to doing another replacement on the same bearing. This could have been prevented if I had just replaced the ten year old struts assemblies along with the new bearing. I will probably do the rear shocks too.

The bad news is that front strut assemblies are expensive, usually costing at least $100 each, but the ones I could find for my model are at least $150 each. I went with a pair of KYBs, one strut assembly for each front side, from shocksurplus.com. The good news is that replacing struts is extremely easy compared to replacing bearings. All it takes is safely jacking up the car, unscrewing or unclipping a couple things mounted to the strut, the two damper pinch bolts at the knuckle, the mounting nuts at the top of the strut accessed in a cubby by the windshield under the hood, removing the old strut and then putting the new one in. You don't even need to remove the knuckle off the ball joint; it just stays there during the replacement process.

Update 2: I DID IT YEEEEEEES! Now all I hear is the engine and no loud bearing humming noise! The bad bearing was indeed the left side.

For anyone looking to do this job here is my list of all parts I needed:
-Sockets: 32mm for axle nut, 27mm (or 1 and 1/16 inch) for the screw in Orion bearing removal press kit, 19mm for lug nuts, 17mm, 12mm, 10mm
-Socket wrenches: a standard, a breaker bar (my 2 ft bar worked great for everything), and a torque wrench rated up to 150 lbf-ft.
-Other wrenches: plier wrench, adjustable wrench
-Needle nose pliers, snap ring pliers (I didn't have the snap ring pliers but I really wished I had because getting the snap ring out took a long time)
-Philips and flat head screw drivers.
-Hammer
-Bungie cord to hang brake caliper
-WD 40 or other penetrating oil, brake cleaner, grease
-Hub remover slide hammer kit (can rent or buy)
-Bearing press removal/install kit (can rent or buy)
-Honda OEM bearing, OEM hub (you don't NEED the new hub but I didn't want to angle grind the inner race off the original hub so I just bought the new one), snap ring (also don't NEED a new one but probably want to just get it)
-Replacement hardware like cotter pins, nuts and bolts. None of this is very necessary especially if your hardware isn't rusted yet, but you can get it to be complete and do what the service manual says to. I bought the hardware Honda OEM from hondapartsnow.com but some of the parts were pretty expensive so you might rather just get aftermarket hardware that matches the specs.

Torque specs (2012 Honda Civic LX Sedan only; even some other 9th gen LX sedan models may be slightly different torque, so check a service manual or ask a honda rep):

-Lug nuts 19mm hex (12 x 1.5mm) (no replace): 80 lb-ft
-Brake fluid hose mount bolt 12mm hex (8 x 1.25mm) (no replace): 16 lb-ft
-Brake caliper bolts 12mm hex (no replace) : 25 lb-ft
-Brake caliper bracket bolts 17mm hex: 80 lb-ft
-Front wheel speed sensor bolt 10mm hex (6 x 1.0mm) (no replace): 7 lb-ft
-Axle nut 32mm hex (22 x 1.5mm): 133 lb-ft
90305-692-010
-Front brake disc rotor flathead screws, two (6 x 1.0mm) (no replace): 7 lb-ft
-Tie-rod end nut (12 x 1.25mm) (no replace): 40 lb-ft
-Replace cotter lock pin (3.0x22)
94201-30220
-Damper pinch bolts: (14 x 1.5mm x57) bolt = 85 lb-ft
90190-SNA-000
-Damper flange nuts
90213-SR3-013
-Lower ball joint castle nut (12 x 1.25mm): 44-51 ft-lb (start at 44 then tighten until pinhole aligns)
90363-S47-000
-Replace cotter lock pin
90701-SX0-003
-Splash guard screws, three (5 x .8mm) (no replace): 4 lb-ft

Other important notes:
-Make sure correct side of bearing goes in. The flatter side that is slightly more off-color (like black/brown) goes in, while the pure black side goes outside. It will be easy to tell based on the original bearing and videos. The off-color side is also magnetic which can be tested but don't get carried away because it's possible to mess up the magnetic alignment inside the bearing.
-Clean things like the inside of the knuckle with brake cleaner and then use just enough grease for everything to press in smoothly.
-You don't NEED new hardware and honestly even the original axle nut would still work fine including everything else. Maybe the cotter pins are more important to replace but if they're not rusted or broken then it should be fine to re-use them.
-Alignment on the front wheels shouldn't be much of an issue on re-install. You can try to get the damper pinch bolts on the upper knuckle to align in their clean marks when re-installing, but they kind of just do that on their own anyway because their isn't much leeway. The front wheels on this model are supposed to be perfectly straight while the rear wheels are supposed to get a slight toe in and camber so it makes me assume the front wheels just kind of sit properly stock without much adjustment besides the toe adjustment on the tie-rod end.

Videos I used for reference:


The first video is like how you would do it yourself and I used that as my primary reference. The others are from guys with a workshop and have a lot of really helpful information too.

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Update: Just adding some info. I tried a couple things to determine if it was a wheel bearing and which side, left or right. I determined it was a wheel bearing by #1 the fact that the sound doesn't change depending on RPM or acceleration, only speed of vehicle, #2 that the sound goes away when turning one direction and gets worse the other, and #3 it sounds like a characteristic wheel bearing failure judging by some youtube videos I watched. To determine the side, I first tried using a mic outside of my car but that wasn't reliable enough. I also jacked up the front, put in jack stands and then tried testing for play on both wheels with not much going on. Then I tried spinning each wheel with my hand on the shock spring, and definitely noticed vibration and noise on the left wheel while almost none of the right wheel. In addition, I always had a pretty strong feeling the sound was coming directly from the center-left side of the car but it was still hard to be completely sure of that just by ear due to the nature of how the vibration spreads across the entire hull.

If the bad bearing is on the left it would be contrary to that common advice that the bad wheel bearing is on the side in which the noise goes away if you turn towards it due to pressure being less on that side during a turn and more on the outside. So due to the vibration on the left spring I'm pretty confident it's the left wheel. I'll also get someone to stand outside and listen as I pass them to see which side sounds louder, then will move on to the bearing replacement.

Here is the video I found that explained why the common advice isn't always correct and how to properly determine which side is bad:
I just got the car and I heard a loud roar noise I'm not used to hearing in cars coming from the front of the car at high speeds. The roaring noise gets loud at about 30 MPH and above and isn't very audible at low speeds. It's hard to tell exactly where it's coming from. I assumed it was normal for awhile, but when I took the car on the freeway I found the noise at 60+ MPH to be so loud it severely drowned out music inside the cabin and thought I should get it checked out.

Link:
https://streamable.com/oc8z91