We put a cheap kitchen counter with drawers from Home Depot and made it an art station and put a peg board over it for art supplies. Will convert it to a tool counter when they get older.

Don’t turn your garage into any thing else. You’ll have all your trash and crap outside.

You really don’t need an elaborate setup. Whatever you kid like to play with. My neighbors do this and they have 3 boys 3rd grade and under. They mainly play basketball, ride bikes, play flag football (they have a small grass area). They do chalk and water guns in the summer. We live in AZ so they are outside every day during the school year.

Roller skating!

Climbing wall

If possible find a way to secure ninja course bands ….one lower for balancing and one higher to grab on to hanging obstacles. Loads of fun for a 7 year old and their friends.

If you can put down rubber flooring as a base layer, it would be fun to turn it into a small gymnastics or ninja area. That depends on how dangerous your kids are with that kind of stuff. I live in a rainy climate and a lot of my child's friends have a setup with rings, a gymnastics bar, an air track, etc.

My sibling lives in Alaska and they set up punching bags and tackle dummies for their very, very exuberant boys.

We have a Ping pong and foosball table in our two car garage. We don’t put our cars in it since there’s more convenient street parking and it doesn’t snow in my area.

They make foldable soccer nets so it can be easily put away.
Bowling ball set is a great suggestion.
DS has a set of Velcro vests and you throw balls at each other that catch on the Velcro

Art easel

Nerf weapons. Sport equipment like a goal and hockey pucks or balls. Maybe stuff like chalk. Im not really sure how much use you will get without a yard tho.

If you don't have a backyard worth playing in, you could keep a low, wooden balance beam in there. Only a few inches off the floor for safety reasons. Maybe a plastic bowling set, dartboard, or other mildly sporty type playset.

If you had a toddler, garage space would make more sense. You want to put messy things there like a small sand or rice table.

7 is old. Probably not going to play house or ride small ride-ons. So I'd go with a craft table, woodshop supplies, and maybe an area to make structures out of big cardboard boxes. Those creativity supplies will do o.k. in a garage and save other areas of the house from messy projects.

We’re moving to a new area and want to use half of our 2-car garage as an added play area. What types of toys, activities, etc. would you keep here for a 7 year old? We’ve never had a garage, or outdoor space, so we’re new to outdoor toys that would be a hit. We still don’t have a yard, but have a parking pad that can be used to play on.