Adobe Enhance: If the sound of a given audio file is not clear/loud enough, or if you simply want to enhance the quality of a recording, you can use Adobe Enhance, a free AI filter designed with podcasting in mind.
If you need to remove background noise (voices, music, distractions…) you can play the audio/video file on Microsoft Stream (included in Office 365/school accounts) and turn on noise suppression.
https://podcastle.ai/: Record, edit, transcribe, and export your content. ($$, some free functions)