My car only has 50k, car runs great, until just wouldn't start,& check engine on

What is your question?

I sprayed carb cleaner on it, started, engine light is off. took to auto zone & codes P0300 and P0171. What should I repair,if the light is off? I don't want to put alot of $ into if not needed. But, don't want to get stranded again although car is running great again. Confused