Starter Problems?

Ok guys I already feel pretty stupid for this but I was at Pismo and my friend got stuck, went around asking for a tow strap, got out of my truck without turning it off, got back in, and it was like a muscle memory type of thing and I tried starting my truck while the motor was on. Almost every time now I go to start my truck it has trouble, at first I turn the key and the starter doesn't turn the motor but I still hear it working. It doesn't happen every time but when it does it usually takes the 2nd time to start up. Need Help

 

btw I have a friend that's saying I need to replace the starter and I shouldn't need to replace the flex plate yet I have another guy that's saying I will have to replace both or I just have a faulty connection, really need some input, thank you