Yo im stoked gg hope you win also my first 

Get proper sleep and keep your scope small. You’ll do great :)

Keep it simple, keep your scope small. Eat good food, drink enough, sleep when you cannot keep awake. At the end remember to add music and sounds to your game. Oh, and a way to get out of your game, when the player has finished playing it (A quit button/ or a pause  menu)

Do something new!
Game jams are awesome for doing new things, especially since you have a deadline it motivates you and you don't work weeks on something that MIGHT not be good. Make sure you learn at least a few things from it and it definitely wll have been worth it!

DO NOT make an inventory system... DONT!!

Keep it a bit small, work on one or two mechanics. Sometimes less is more, this ALWAYS counts for game jams.... ALWAYS

Anyways overall just have fun, try to learn some things and do something new! If your game isn't great upload it anyway! Might just get some constructive feedback! Most people in the gamedev community are very nice!

Use post-processing

Follow some things by brackeys from his YouTube channel

Finish the entire game before even thinking about aesthetics whether that be art or music.