Intermittent crank no start. Help!

[Courier_292]

I got it back in November and it ran several times with a little trouble, but by mid-December, it would not start on almost all attempts. I’m not very skilled with cars yet, so I’m kind of stuck. I replaced the fuel pump, crankshaft sensor, and spark plugs. I think fuel is good, so I’m not sure what would just fail or work intermittently, or maybe I messed something up. For example, it started today, but when I turned it off, it would not come back on after many attempts. Thanks for any help you can provide.