External hard drives

Hi all, I’m new to the forum so please be gentle with me 😀

I have used iPhones for many years and I have now decided to make the final transition from PC to MacBook. I would like to transfer all my mp3 files to an external drive and then store selected files on the Mac for my iTunes library - is there anything I need to be aware of before I take the plunge? Any recommendations for the drive?

Many thanks in advance 👍