Playing to backing tracks

Hello ,I’m very new to this. I buying an eleven rack, what I like to know how can I record over backing tracks.
Do I put a CD in my laptop. Or can I download mp3 wav files on line.
Thank you.

This one?
Do you play guitar?

Yes I’m an advanced guitar player. With poor tech skills.

It’s better to work with uncompressed audio formats (like WAV) rather than compressed formats (like MP3) because MP3 encoding reduces the sound quality and that loss cannot be recovered - only made worse.

If you have the backing track on CD, “rip” (digitally extract with EAC or CDex or similar) to make a WAV file of the track.

Import the backing track into Audacity.

“Overdub” your guitar part.

Details about overdubbing can be found in the manual here:
and the example using a Behringer UCA 202 will be similar to using other USB interfaces (the UCA 202 is a very simple device - the “eleven rack” may require more setting up - I’ve never used one, so refer to the manual and their on-line support for details specific to that device)®_UCA202_Stereo_bidirectional_USB_Sound_Card

The eleven rack appears to normally come bundled with a copy of Avid pro tools, you may want to use that and not Audacity at all.

There is a possibility that the eleven rack may not work with Audacity.
Some hardware products from Avid are designed to not work with audio programs other than their own (ProTools).
I’ve never used an eleven rack, so I don’t know either way, but if using Audacity is an important consideration, you should check that out before you buy.