Need to paint the interior of my garage. Thinking of an Eggshell
since it can be washed. Was overwhelmed at Home Depot with all the
paint and could not get a good answer at the store. Any help here as
to what would be a good quality paint for this purpose?

Eggshell/satin is fine. Semi-gloss is more washable, so it's a
question of how dirty you think it'll get vs. your preference for
sheen. I dislike high sheen walls.

I used Glidden "flat" latex in my garage. I think the color was "antique
white". It's one of their standard premixed colors. Makes for a quicker
trip in and out of the home center.

I keep seeing "washable" mentioned. I've never had any problems wiping
spots off the paint, but I don't make a habit of washing down the walls in
my garage. But flat paint seems just as washable as paints with more sheen.

If you're painting over new drywall, wipe down the dust then paint on a PVA
primer, and follow with one or two coats of your final paint color.

If you're painting over an existing finish, wash down the walls with a TSP
solution first. This will remove dirt, oils, etc., and prep the surface for
the new coat of paint. Then apply your paint after it dries.

Anthony