Audacity out of the box should be able to do all these jobs with the exception of making an MP3. Audacity will not do that without adding the Lame software (copyright issues).
Microphones are always the sticking point. Cellphones use all sorts of fancy tricks to isolate your voice from your environment while you’re talking, but nobody would consider cellphone voice to be good audio unless you were reporting from a war zone.
Does everybody have gaming headsets? Sometimes you can get Audacity to record one of those, or at least the microphone part. Push the microphone boom a little way from your lips so you don’t get breathing pops and gasps.
The Radio Shack 3013 lavalier (tie tack) microphone is not awful for budget-free productions.
It has its own battery and so it’s not subject to computer soundcard problems. Plug it into the pink Mic-In of your computer. Almost all computers have them now.
Most computer soundcards have one benefit. You don’t have to buy one, but their noise and distortion performance can cause problems. For that, I use a tiny USB soundcard such as the Startech ICUSBAUDIO.
That’s one connected to my telephone recording microphone.
Other people certainly make them. That’s just the ones I have. Out of four, one arrived partially broken.
You do run the risk of the cellphone getting into the microphone. If your nearest cell tower is miles away, the phone will be at maximum power and you may get odd ghost sounds in your sound. Separate as much as possible the microphone and its cables and the cellphone.
You should do a “fake” show no matter what it sounds like just to get the coord and production swing down. This is very much like juggling cats and there’s no such thing as being late.
That’s a very close cousin to how this video was done.
I know it looks like a Skype juggling act, but it’s just four files shipped between cities. It could have been done through the mail.