I'm new to switch2osm and I've created an OSM Tile Server with switch2osm on Ubuntu 16.04 LTS. It uses Apache, Mod_tile, renderd and Mapnik to render tiles. It uses PostgreSQL as DBMS and osm2pgsql to import Open Street Map shape files to database (I've downloaded my shapefiles from Geofabrik).
I want to add my own layers (like my GPS data of my organization) to PostgreSQL and style them through Mapnik to be shown on the tiles. How can I do this?