how to get different parts of recordings in a new recording

My girl wants to do a report on a creative way. She did some interviews and now she wants to make an audiodocument to mix parts of the interviews in a text spoken by her. In Audacity it is is not clear how I can select parts of interviews, store them in a folder or map or anything and, later on, getting them from the map and mixing them in a new recording.

You may want to use the commands in the Edit Menu to cut or copy a selection then paste it in a new Audacity track. If you need to create a new track, use the Tracks Menu.

If you want to work on it over several days, save it as an Audacity Project The project can contain multiple Audacity tracks. Export a WAV as backup before you close the project for the day

Reopen the saved project. If you have recordings already as separate audio files, import them into the project

All Audacity tracks above one another in the project are implicitly mixed. Use the gain and pan sliders on the tracks to adjust the mix