Spoken-word audio has its own rules: clarity over color, consistent loudness over dynamics. These guides are written for the podcaster who edits their own show and wants it to sound like a produced one.
Fade audio in and out in Audacity 4 with the Fade effects or the clip gain line, how long a fade should be, and how to crossfade two clips.
Where to find royalty-free music for a podcast: free sources, music you buy once and keep, and subscriptions, with the licence terms that matter for each.
Echo makes a voice sound far away, with a tail after every sentence. To remove echo from audio, you have to separate the voice from the room it was recorded in. Extract:Dialogue 2 by Acon Digital does this in real time and gives the voice, the room reverb and the background noise a fader each.
Build a vocal chain in Audacity 4’s realtime effects panel: EQ, compression, de-essing, color and a master limiter, with free effects first and plugins where they help.
Put each voice from a one-mic interview or call on its own track: by hand in Audacity 4, or automatically with the Speaker Splitter plugin.