First of all, have the wall where the screen will be finished as smooth as the Finishers possibly can. Stress that requirement. If you manage to get them to leave you with a ultra smooth wall, you'll be on your way to optimal performance with a minimum of effort.
If my past experience with a slew of 8350s counts for anything, I can safely state that you do want to use at least a light Neutral Gray paint. Better still, a moderate shade of Gray with metallic content. The ability / willingness to spray on your paint will open many possible choices. Rolling is your other option, but somewhat limits you to simpler, Flat Neutral Grays. Spraying is simple and very inexpensive these days, so give it strong consideration.
Your a NOOB, but that doesn't mean you don't want jaw dropping results.
Paint your walls a medium dark shade of some Earth or Water color, in a Flat sheen. Do the Ceiling in the same color only 3x darker. Just that bit of effort will also add an enhanced level of Projector Performance because the room will not work to detract from the dynamics of the Image.
Just give up a little more detail about what your wanting to do, the dimensions of the room, seating distance, and desired / hoped for Screen size, and we'll get you on your way.
Hmmmmm, last word here.
Grays of various shades, be they a simple Neutral version or a more advanced Metallic based mix, can and do provide color correct images and far better perceived contrast than any White possibly can. If the 8350 was instead a 6020 w/350,000:1 Contrast and the room was a perfectly Blacked out space with NO light reflections off any wall / ceiling.........well, white would be all right.
But a light, neutral Gray.....even better.