Hi Ginny, You'll want to use a masonry paint. Here's a link that may help: https://www.bobvila.com/articles/how-to-paint-brick/
You can use the same on the inside of garage if it's cinder block.
Ginny, check out this site: It's one of my favorites.
You can use either concrete paint or exterior paint. Behr makes both and both are good.
Hi Ginny. I'm Cindy. Start with a quality acrylic latex primer. Then paint with a good quality acrylic latex paint. I believe that when it comes to paint, you get what you pay for. Also, the higher the paint sheen, the easier it will be to wash and clean the surface. Wishing you all the best.