Question

I am very new to all this, and this might be a dumb question. Is there any way to import a song to studio one 3 and just records vocals to that song?

Answer 1

You can, yes.

Typically that would be done with backing tracks, maybe a backing track someone made for you or a backing track from a Karaoke CD or similar.  It should work fine with *.wav and *.mp3, but the latter won't work in Artist unless you have the mp3 add-on for Artist.

https://shop.presonus.com/products/software/studio-one-add-ons/MP3-Converter-for-Studio-One-Artist