This game jam series is also about gaining skills, so sure you will struggle at the beginning, but it's for the good, like anything we must learn to master :)
On the artistic side, there is no good or bad. Feel free to have bizarre graphics and sounds, that's also interesting.
The one hour rule is here to put a scope. Don't try to create a top-seller game, stick to one mechanics and explore it widely. But then, you can exceed a bit the deadline.