Scratching over music with one turntable?

I’m 17 and really want to learn how to scratch, but I’m still figuring out what equipment to get. I’m on a budget, I was hoping I could start with one turntable and a mixer + my laptop. After some research, I know that you can, but I want to scratch over music/instrumentals. Would this be possible with one turntable if I played the music through my computer? Hopefully I don’t sound too ignorant and I would appreciate some help!

Edit: Thank you all so much for the help I love this community :)