i was driving down the highway at about 80 and my check engine light came on, the code means that my number one cylinder is to lean wtf does that mean?

 

It means your car is running lean...not just the #1 cylinder. Inspect your fuel injectors.

 

P0171 is the OBD II code for bank one lean. Since your Neon only has 1 bank, it means your entire engine is running lean. Low fuel pressure, clogged fuel injectors, vacuum leaks or MAP/MAF reading incorrectly are the usual suspects.