"Cleaning up audio" is too generalized. Be more specific and post a clip on WeTransfer, in Dropbox, or on another cloud storage/ files sharing site, and someone may post suggestions.

"Garbled audio" can mean many things. If it is analog based distortion, it can be difficult to impossible the eliminate. A few digital 'overs' can be easily fixed though.

Muffled sound can often be made more intelligible with a Equalizer (EQ) plug-in, A high frequency 'Exciter' is another or additional option but AFAIK, VP does not have any included.
VP has a few EQs to choose from. Track EQ is a simple four-band paragraphic EQ that has boost/cut notch and band-pass filters. There are many, many EQ plug-ins available to download for free or otherwise. Exciters are not as plentiful but are 'out there'.