While the bike itself has probably been a bit abused (almost ALL of them have been), the VTR mill is a Stone - it's highly unlikely it's actually "broken" unless the PO ran it out of oil or dumped it into the creek or something. Most likely it just doesn't run because it's been sitting.
Seek the opinion of someone mechanically knowledgable that you trust, if you can't diagnose the problem yourself. Buy a manual. Don't be afraid to get your hands dirty.
That said, Honda only made these bikes from '88 to '90, so there's not an enormous aftermarket left laying about. Some parts on the '90 don't directly interchange with earlier parts, be certain of what bike you have when searching for parts.
Things like brakes, fairings, lights, front suspension, etc. - can all be adapted from newer, more-plentiful bikes, if you're clever.
Even at its age, the VTR 250 was a superior all-around bike than the Ninja 250, 'cept maybe for the '08 (haven't ridden that one yet too know if the changes make it surpass the VTR).
Honda SUCKS for not importing the current VTR to the 'States.