Far Cry 4

This is an easy achievement. Gaining XP in Far Cry 4 is easy, especially with all the stuff you can do. Assuming that you are still low-leveled, the best thing you can do is absorb yourself into the game. Go out and wreck Pagan Min's army any way you want; almost anything gives you XP. Headshots and takedowns are the best ways for a new player, though. Once you level up, use your new skill points to unlock whatever you want. (Some skills will require two points.)

Karma events, supply truck deliveries, and side quests reward large amounts of XP, so don't pass up any if you can.

All in all, this is an simple achievement with many different options. It will help you get a taste of the action if you haven't already.