I see what you mean, OP did not state how low it was.
+1 Honda fluid is the right stuff.
I just saw it low so i add 2qts. so was my bad not to make sure how many i need to add. I add a Castrol ATF for honda cars. but the fluid issue comes after the issue of 1st gear that i describe first. I just change the Solenoid but the issue stay the same.
First thing I’d do w/that problem is a proper transmission service. How that’s done varies car to car, but usually it means to drop the pan, clean the bottom of the pan while looking for metal debris, replace the filter, then re-fill with the proper Honda fluid. If that helps but doesn’t fix it 100%, drive for a couple weeks, then do it again. If that still doesn’t work, then you’ll need to consult a well recommended independent transmission shop. Ask your regular mechanic who they use for their own car’s transmission service and repair needs.
A misfire will cause you to use more throttle opening to try and get more power and will drop the vacuum and make the car downshift early and seem like a slipping transmission.