Total newbie help me out building my first pc

basically what the title says, the most experience i have with computers is my m4 macbook, but i am expanding with video editing, and music editing and etc etc and my little macbook is screaming for help. I am basically a baby learning to walk, on top of this my boyfriend has been wanting a pc too so i figured id kill 2 birds with 1 stone, a gift for him and myself. I have looked into pre builts but everyone has steered me away (really i saw someone say their prebuilt caught on fire and i got scared lol) Anyways, i need someone to start at the beginning everything from what i need, what i should get even if not technically needed, even if you think its stupid small things that are common sense still tell me because i promise you there is nothing up there when it comes to pc stuff. I would like to stay on the cheaper side of things i dont really have a set dollar amount but probably not over 800, preferably a bit lower. I would only be using this for editing and stuff, and my bf would onle usingit for games, Fortnite, car x series, forza, nothing crazy. Everything from the monitors to keyboards, just tell me everything, i am not in a rush to build this so ill be buying everything piece by piece. TIA