Idk how anyone with experience feels, but I think you should just go for it. Before like 2 months ago I hadn't written any fiction in about 2 decades (fuck i'm old), drawn anything in about the same amount of time, and knew barely anything about programming. I'd been contemplating making a game for years, but kept putting it off until I finally said, fuck it, and just jumped in. 

Since then I've written a few fics, bought a cheap-ish art tablet to learn digital art (so many youtube videos), played around with renpy, and took a python class to learn the basics. I know myself though, if I try to wait until I'm satisfied with my skills I'll never actually finish anything, so I made myself join the jam to force myself to finish something. It might end up hot garbage, but at least I will have done it. 

Whether you join a team or make something on your own I hope you decide to join the jam! I will look forward to playing whatever you make :)

After the voting ends, you can do whatever you want!

each game can only have 1 submission, yes. but on the game, you can add team members as contributors/authors so they also have voting access 

I'm not quite sure how itchio will display it to you, but it should hopefully show up like now somewhere where you can see jam submissions

ok! I looked into it more. how it works for all jams is that entries with less than the median number of ratings get a small penalty applied to their score, mostly because it's hard to get an accurate rating if there are less votes to aggregate. the way ludum dare does it (which i like) is that you don't even see your score/qualify for ranking unless you get a certain number of votes (20), but there's not a way that i can see to implement that on itchio unfortunately.