Joke aside, look into Stardew Valley and Animal Crossing : New Horizons home decor tutorials. They give you great ideas and the most important part: they don't try to shill some brand/furniture/home decor course
Also, you should put practicality over everything else, function is the most important. You need a big desk for you hobbies but it looks kinda goofy in your small room ? Not a problem it is functional.
For arranging your furniture check out Dear Modern's videos. The things he says sound kinda like spiritual stuff (idk if you are into that, it doesn't matter tbh), however the advice is solid and it will prevent you from feeling bad in your room due to the furniture arrangement.
Good luck with creating a room that will fit you !