Assuming this is the TD27, Audacity should allow you to start with any number of tracks from 1 to 28. I would start with 2.
If you want to try, say 6 tracks, select this number in the drop-down list. Then record.
If you want to label the tracks, try creating 6 empty tracks with Tracks > Add New > Mono Track. Label each empty track with Roland’s track name: MOL, MOR, DO1, DO2, Kick1, Kick2. Save this “empty” Audacity project. Then load it in for each recording and Save As for each new recording.
Reload the empty project, and record in to it.
Although Audacity will do multi-channel recording, it is NOT multi-channel friendly. For example if you decide you want to record only channel 23, Audacity is going to require you to also record channels 1-22. In my opinion, you would be much better off using Roland’s recommendation: Pro Logic X. There is documentation and video tutorials for using your TD-27 with Pro Logic X and there is a 90-day free trial for Mac. I would start there. At the end of 90 days, you are welcome to come back here. You might also want to look into Cakewalk at that time. Spoiler alert: Audacity is currently drawing up plans for improved multi-track recording and in deed might have something to show by 4th quarter of this year - just about the time your free trial is ending.