OGA winter '22 jam was actually my first ever jam, or at least the first I actually submitted to (I tried Ludum Dare a couple months before, but did not end up submitting a game due to running out of time and insecurity about the game itself). I personally find jams to be good for making games because there is a deadline you need to finish by and a ready made audience of fellow jammers to play, comment and give feedback for your game, and vice versa. This jam is definitely a good one to start with because it is long enough to have plenty of time to make a game, the voting segment gives extra encouragement to other jammers to play your game and you usually get good constructive feedback.
My main advice is aim small, since aiming too big has usually been my main mistake in jams. Good luck on your game!