a stupid question as the answer will likely be an easy one
Not so easy if you’ve never met an audio editor before.
There is one fair warning. Never, ever do production in MP3. MP3 always produces sound damage and you may not hear it right away, if you try to create a show with one, you may find the damage doubles in your final show and the damage nails you right to the wall.
There was a podcast version of a popular broadcast radio show that had a leader at the front. “This podcast is brought to you by Squarespace…” and then it sailed right into the radio show. The radio show sounded very, very nice because they got it from the original Broadcast WAV files, but the leader was an old MP3. So what it really sounded like was:
"This [bubble] podcast is [honk] brought to you [gargle] by Squarespace [echo].
I see it doesn’t do that any more, so some producer must have caught on and changed it.
This also kills people trying to download highly compressed music to make an award-winning podcast on the cheap. Good luck with that.
Anyway. Import all your tracks one right after the other (File > Import). Audacity will stack them up vertically and play them all at once. The trick is to use the Time Shift Tool (sideways black arrows) to push each track sooner and later until they appear at the right time, and then the Envelope Tool (two white arrows and bent blue line) to increase or decrease the volume word by word as needed.
I make that sound so easy, but that’s the short narrative version.
When you get it to sound perfect, slice off the end bits you don’t need (drag-select > Delete) and File > Export as WAV. After you get a perfect archival WAV file, then File > Export as MP3 or whatever your final deliverable is. You should also Save a Project. A Project is cool because it will save all your tracks stacked up in place in case you want to move or change something later – but it’s not a sound file. Audacity will not Save a sound file and Projects do not save UNDO.
You could run into troubles with sound overload because basically, Audacity is adding up all your tracks. Open the WAV export in a fresh Audacity and turn on View > Show Clipping. If you have no red lines inside the blue waves, (overload points) you’re good to go.