How do I recover the hundreds of songs I purchased on Itunes. I purchased an IPhone 8s a few years ago the music did not transfer to my new phone

Your music library should be housed in the iTunes program on your computer. That is where you backup your iTunes library/purchases, etc. You would then sync your music library to your new device. Sync your iPhone, iPad, or iPod using your computer - Apple Support

If you do not have your iTunes on the computer, then you will need to re-download the content individually.

As I said, your music library should be in your iTunes on the computer. If you were using iTunes match, they would have been replaced when you uploaded that library to iTunes. How music sync on the iPhone works depends on how you managed it. Now they have Apple Music, their subscription version, and your music is all streamed, unless you decide to download something. Music you ripped to iTunes from CDs or other sources should still be on your computer in your iTunes library. Then syncing to your library is how you get them back.

How did you get music on the iPhone 8 a few years ago if it did not transfer? Where did you get this My Girl that you said is not your original?

The songs transferred over are NOT the original songs I purchased years ago. Example - My Girl by Temptations - is gone & replaced by an Awful!

version - now My Girl by Otis Reading .