I purchased music thru itunes and scanned cd's on my PC. How do I transfer all this music to my Macbook pro?

Hello BigmaxxS and welcome to Apple Support Communities. It appears you are having some difficulty moving an iTunes library to a new device.

How to move your content to a new Mac

In the case of music content, you can also use the Sync Library function of the Apple Music service or iTunes Match.

Subscribe to iTunes Match

Turn on Sync Library with Apple Music

Note that in iTunes on your PC, the feature is still called iCloud Music Library.

Cheers.