New and Needing some help

So I have a 1995 Specialized Rockhopper A1 Comp I got a deal on at a garage sale...$20. I've already replaced the cassette, shifter cables, seat , new 26x 1.75 tires and had it lightly cleaned.

I'm wanting to build a gravel grinder out of this but wondering if it'd be worth it and what I could...