To check fluid level in a Honda Automatic, you bring the vehicle up to operating temperature, park vehicle on a level surface and shut vehicle off...then check reading on the transmission fluid dipstick. As netfreak said...check fluid condition and odor. If fluid is dark and burnt you may have a transmission issue aside from the shaking or in addition to.
As far as the shaking..check your axles, suspension, tire condition and make sure your lug nuts are tight
. A lot of the shaking issues on vehicles have a lot to do with tires believe it or not! lol So start with the easiest most obvious things to check and go from there. When checking the axles move the inboard end of the axle side to side to see if there is any differential play in the transmission. Check the axle seal area for leaks. Check those items and come back and let us know what you find. Good luck!!