To get you started, we've provided some example solutions for past CTF challenges in our write-ups repository.
Pwntools is best supported on 64-bit Ubuntu LTE releases (12.04, 14.04, 16.04 and 18.04). Most functionality should work on any Posix-like distribution (Debian, Arch, FreeBSD, OSX, etc.). Python >= 2.7 is required (Python 3 suggested as best).
Most of the functionality of pwntools is self-contained and Python-only. You should be able to get running quickly with