There are a whole lot of samples that come with the Tracker Mini. They are mostly organized by genre, techno pack 1, 2, 3, etc. There are about 10 genres including sampled acoustic instruments like piano and guitars. There are some loop cloud packs included that have longer loops and a wide variety of samples.
.pti file formats are used. You can back them up but they are unique to the Polyend Tracker. You can’t open them in renoise, there is an export to .it function but it is far from flawless as there is not feature parity between Tracker DAWs and Polyend Tracker as well as some bugs and quirks with the file import/export for .mod and .it files.
You can export songs, song stems, patterns, pattern stems and record via 14 tracks of audio usb for Windows and MacOS devices with Tracker Mini. So there are a lot of ways to get songs onto a computer.
Easiest way would probably be recoding MIDI via USB direct to the DAW.