Here are a few free software options for recording solo acoustic and voice:

Audacity: Audacity is a free and open-source audio editor and recording software. It is available for Windows, Mac, and Linux. Audacity is a powerful tool that can be used to record, edit, and mix audio. It also has a number of effects that can be used to improve the sound of your recordings.

GarageBand: GarageBand is a free music creation software that is available for Mac. GarageBand is a great option for beginners as it is easy to use and has a number of features that can be used to create professional-sounding recordings.

Cakewalk by Bandlab: Cakewalk by Bandlab is a free digital audio workstation (DAW) that is available for Windows. Cakewalk is a powerful tool that can be used to record, edit, and mix audio. It also has a number of effects that can be used to improve the sound of your recordings.

Looking for a free and easy way to record solo acoustic and voice, Audacity is a great option. If you are looking for a free music creation software with a bit more features, GarageBand is a great option. And if you are looking for a free DAW with a lot of features, Cakewalk by Bandlab is a great option.