The first thing you'll need to do is check for leaks underneath the car - this will give you an idea of what's perished/leaking and what isn't. If you just want to get it running, then you'll need fresh fuel, a fully-charged battery, and a fair wind. Even though it's only been standing a few years, you could be at the mercy of a few things like a stuck clutch or that failed fuel pump. If it was a non-runner when you bought it, then I'll hazard a guess that the car needed more than a new fuel pump. You don't say whether it's a petrol or a diesel - if it's the latter, you'll probably need to bleed the system to get it going. If you're a bit out of your depth, then call in some help.