Clone into your server's addons folder.
TeddiO/gFwens for Steam groups.
Place your OS' specific binaries into garrysmod/lua/bin
.
Database module should work with any SQL complient relational database. (MySQL, PostgreSQL, MariaDB, etc)
Copy template.env
to your garrysmod
folder and rename it to just .env
.
Edit it's contents to use your SQL credentials.