Tips for converting a garage?

Firstly I want to start by saying that it isn't really a garage (lmao baited) but it's close enough that I thought I would probably get more help by calling it as such. That being said this is more to hold myself accountable because I should probably be more realistic considering I currently have a grand total of 3 friends on here (ha!).

Technically speaking, it's an undercroft. Below is a pretty good example, but half of our area is gravel instead of concrete:

It does have two power points (although in pretty inconvenient places) and a tap (unsure whether it's drinkable but i assume so...).

Currently, my plan is to divide the space with sheets, blocking off the gravel area so we can make effective use of the slab. Then I'm thinking I will hang up some fairy lights. Ideally I would like to add an easel down here so I can paint, then maybe a desk/work bench for various projects.

I am kind of clueless though so I would appreciate any tips on making it feel a bit nicer. The only thing to keep in mind is that I am renting so any changes would have to be able to be removed with no damage to the original structure (although this is lenient within reason as I highly doubt the owner would notice things like screw holes from hooks or the like as its kinda a shit show down there).