Behind starter fly wheel only moves back not forward wil not start not start starter seems like its working spins

Remove the starter and replace it engaging the teeth sequence so they are locked together, you cant just put on on it without interlocking the teeth, take it loose then reposition it with teeth engaged then tightern bolts and solenoid you are good to go.

Disconnect the battery and then carefully remove the starter. Take the unit to a local auto parts dealer for a bench test. Starters have two separate functions, one spins the shaft to crank the engine, the other is called a bendix, which pushes the starter gear out to engage the flywheel, and then after the engine engages, retracts it (except in the case of starter/generator combo units which recharge your battery and power your vehicle's electricals while the engine is running) Always best to get a bench test rather than depending on apparent symptoms.