Old Garage pit with bricks?

Ok so bought our first home. Built in 1900 and the garage is built very odd. Half the garage has concrete in the front and towards the back there is a “pit” accessible from the back. Almost like a garage cellar?

Anyway it’s a two car garage. One half is filled with bricks and I hear the older lady used to park her car there. The other half has wooden boards that enable you to work up top in a garage shop kinda set up. My questions are.

Can I fill the back pit with a bunch of bricks and it would be safe to start parking my car there?

Secondly, is it safe to use the other side that has the bricks already there?

And thirdly, has anyone ever seen this weird set up? I’ve never seen that before and can’t find it online anywhere.