Hi there and welcome to the forum!
I have a 12" 40W combo amp and that’s plenty for bedroom practice. Smaller speakers can work at lower volume - you’d be missing a bit of low end, but hey.
People here on the forum have good experience with the Fender Rumble 40 and 100. Markbass makes a nice 8" mini amp. Phil Jones has great stuff in the mini department, but it’s pricy.
You could also go for a Sans Amp or SGT DI. These pre-amps can be combined with powered speakers/monitors and deliver a small setup with crisp sound.
Well, depends on your budget and the room a bit. How much do you want to spend? Do you have a dedicated practice space? 
Also, feel free to introduce yourself: Introduce Yourself! (2024)
Cheers,
Antonio