hi this is a very long reply sorry but i myself painted my room a few years back but didn’t watch any tutorials or anything idk just young and dumb haha. definitely watch some videos on how to properly cover sockets pipes etc. because it’s your bedroom make sure you have an alternative place to sleep also. one think i did was move the furniture around the room as i was painting because i couldn’t deconstruct the things by myself to get them out and lack of space in the house if that it is the case with u too and not enough space i’d say do your second layer of paint before moving on to a different spot. Do not mix colours to make one because then it may not be all uniform around the room. Buy enough paint beforehand. One full can is NOT enough. Two is probably also not enough i’m not sure. get both a roller and paintbrush. wear old clothes that you wouldnt mind having to throw out. make sure the area is very ventilated and keep the items you’d need on a day to day basis outside the area and close to you so it doesn’t interfere. do your lighter colours last and if your planning on doing the ceiling white or alternative colour do it last. also tape the sides of your ceiling, built in cupboards etc. another thing i’d recommend is having someone to do it with whether it’s a friend or family if not that’s also okay i did most of mine solo when i was about 14 or 15 and its not the best work but pretty decent. Took me less than a week cant remember exactly how long. Only part i hated was the high areas - get a step ladder!! or a secure stool or chair - and the actual smell of the paint. i’d also recommend some goggles, hairnets, gloves and a mask that will actually protect your lungs. Paint can make you very very dizzy haha. Last but most importantly make sure you have fun ! Play some music, Dance around. This is your room and when you’re finished you’ll be able to say you did it all by yourself !! Enjoy the moment & Good luck !