250-500cc NEEDS SOME HELP! looking at used wr250

OK, first post, I'm new and I am about to meet a gentleman about a 2000 WR250. I rode bikes as a kid and was looking at a yamaha ttr230 and a yz250f but the guy with the yz said that this is a much better trail bike which is what i am going to be using it for. When i check it out what are some key things I should be looking for. Obviously when was last rebuild, I was told if real easy to kick the engine doesn't have good compression. Anything I should keep an eye out for, anyhingn with suspension etc. Sorry for all the stupid questions, I know I sound ignorant and that is because I am mostly so any helpful advice would be much appreciated!

Thanks