Usually, when I'm new to a game, the first thing I do is open up the server query window. I sort the servers by map and download whichever maps are the most popular. If you don't plan on hosting a server, I wouldn't bother downloading slate edits unless you really want them. I'd download the maps that have the most custom content so that you don't have to wait a long time to get into servers running them, like all the GTA maps. My favorite custom maps are the Celestial Dreams port, Autumn Pond, Earth Orbit, and the Forest Maps by Nate.
If you want my personal recommendations for mods, I would recommend the Zombie mod, the sniper rifle, the minigun, the biplane, the pill, the stunt-plane, the remote bomb, the parachute, the scooter, the macro saver, the door and teleporter mods,
rise of blockland beta, the fill can, the duplicator wand, the stunt buggy, the box truck, and Space Guy's portal gun.
