Today my engine started revving while in park for the first time. It went up and down from about 1k to 2k pretty rapidly. I'm pretty new to Hondas and this car has been starting to act up quite a bit lately. What is causing this and is it a sign of a bigger problem?

 

as weird as it might sound, check your coolant. Low coolant seems to screw with the idle on these cars. What do you mean by acting up quite a bit? listen for any hissing noises around the engine while its idling too

 

As stated above, you are going to want to check your coolant level first as coolant does play a big part in the idling of any Honda. If your coolant level is ok, your problem is more than likely going to lie in your IAC Valve. This is normally located either on the T/B or in your case, it is mounted on the I/M. If you need to replace this, you will lose some coolant during the process. After replacing you will need to top off coolant level in radiator and "burp" the coolant system to ensure proper operation.