Acera? Alivio? Aluminum frame with a possibly beat-up suspension fork that you're considering swapping out?

I would definitely find a different bike, I think it would be bad money to buy that to sink any money into it. You can find nicer older steel frame mtbs for not a whole lot of money. Why not just look for an 80s road bike or even a 90s steel framed hybrid? Sounds like that's more what you're looking for and buy the time you spend money on 'upgrades' to that schwinn, you'd probably have spent about that much, and you probably wouldn't be able to recoup the costs by selling it eventually when you do get a different bike.