How do I record my guitar while playing a backtrack?
Audacity calls that overdubbing.
https://manual.audacityteam.org/man/tutorial_recording_multi_track_overdubs.html
Note one important restriction. If you plug your headphones into the computer, you will not be able to hear yourself as you sing or play. If you have an approved mixer or interface, you should be able to hear both you and the backing track at the same time.
Write back how you get on.
Koz
I’m using Focusrite scarlett 2i2. connected my guitar and head phones to Focusrite. Converted backtrack to mp3. I want to play guitar and record backtrack at the same time, then play back and save. How can I do this.
What is your “backtrack”? Is it an audio file, or a vinyl LP, or what?
audio file
Then there is no need to record it. Just import it into Audacity, and then overdub as described in the tutorial.