FingerpickPro Lite is a FREE cut-down version of FingerpickPro, which is scheduled for release in early months of 2022. Try before you buy! For more details go to the FingerpickPro page.
You'll find plenty of information on the Pick-and-Strum Guitar page.
StrumTracks products are in SFZ format, which means you will need the free Sforzando player from Plogue. See here for details.