I'm trying to change some colors around on a picture of my house, to see what color scheme would look best on it interior and exterior wise.

I've never used photoshop at all, but am very good with computers (i know, sounds weird, but its true. lol)

How would I go about changing colors of things, if someone could say take a screenshot and circle what buttons to click, etc. that'd be great. I was up for an hour or so trying to mess with it last night before bed and just got frustrated and turned the computer off.