Being a natural do-it-yourself-er, I would want to take this on, but I am forced to agree with Matt4x4 that you should take a pass on it. Here's why:
1) without directions you may well assemble it incorrectly--that is terribly unsafe.
2) The rumpled wall may be far less serious than you think--a roller press may clean it up. But the point is that the condition of the unit is dubious.
3) You will have to find the correct liner and figure out how to install it as a stone-cold beginner.
4) Here's the biggie, to my mind. Since you do NOT know the dimensions of the pool, you have NO idea what size site you need. An 18x33 oval requires a very different site than a 30' round. If you make the site too big, you've wasted enormous time and money. Make it too small and you have expand it--and it may be in a direction you cannot go. If you knew the size and shape it wouldn't be an issue.

So...unless you are super-adverturous, super-handy, and super-broke, I'd say give it a pass.