Quote from @Christian Bland:
If you've used a sprayer before, it's so much more efficient. The longest time with the sprayer is taping everything down, but once that's done it's pretty easy.
Rene, Christian is correct here but let's figure the entire setup and tear down. A sprayer will need to be cleaned and you will likely use a brush and roller as well because the paint will not be the same everywhere.
You will probably want to use flat on the ceilings to hide imperfections. The door trim, window trim and base will want to use semi-gloss. the walls will be an eggshell likely so you can wipe away most dirt.
Typically you want to cover all floors and windows and items to remain unpainted like ceiling fans, etc. This is bagging and taping.
Then spray the ceiling and the floor trim. Then cut in w brush and roll the walls.
It's up to you what to do but educate yourself on the setups of spray. Most DIYs will simply use a brush and roller due to the simplicity. The 900sf is not massive so I don't thing spraying will benefit much imo. Good luck and congrats.