Wow, that is a broad question.
Do you mean having a Project with multiple tracks or recording multiple tracks at the same time (mulit-track recording).
For multi-track recording, record-enable all the tracks you want to record with the Record Enable button. THis Track Header button is hiden by default and has to be shown.
However you can record only as many Audio Tracks as you have separate audio channels on your Audio Device (Select the input channels in the Smart Controls Inspector)
Hope that helps
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