I'm looking at cars on Craigslist and my friend said I should get a 98 civic because he has some parts for it that he could give me. I saw one listed at $800 the car had about 200,000 but the person said they just rebuilt the engine. Does this mean it's a good car?

Rebuilding a motor costs more than $800. The complete car for $800 sounds like it's too good to be true. I'll bet the owner tried to do the work themselves and something went wrong!

Get the name of the shop where he got it rebuilt or a receipt. Now if that all checks out then maybe it's a decent car because the engine may be newish but the rest of the car is another gamble.

AN 800 dollar car of that vintage? The owner wants to dump it.

the seller can say whatever he wants to but w/o written proof of the rebuilt engine + all other written service records, it's a big gamble

Or you could take someone, who knows what they are doing, to go and inspect the car with you.