Can't transer music from iTunes library to device?

I recently got a new laptop but I've been having a really hard time setting up my iTunes. On my old computer I was some how able to transfer all of the music on my phone into my iTunes library and now I'm unable to do that. Also, what songs I do have on my library, I'm unable to add these songs to my phone. So basically my iTunes is a major suck-fest and I'm unable to transfer any of my music among my laptop and my phone. If anyone could offer me any advice on how to take care of these issues I would greatly appreciate it. I'm using an iPhone 5 and an hp laptop.

Try updating your iTunes to the newest version

From what you described, I can see you are not good at using iTunes. Here I suggest you use FonePaw iOS Transfer, which enables you easily transfer music from iPhone to iTunes and vice verse.