You will get this achievement pretty early in the game.
You see it on screen when you levelup, to level up, go to the magic, item, map skill screen and press up twice.
You level by leveling your skills. So make sure you use a lot of magic spells and fight with different weapons. Make sure that after each time you level you spend your skill point in your skill tree. The only way by not getting this achievement is avoiding all monsters, never use magic and don't level your skills.
Train all skills and you will get this in no time.
Some easy ways to level:
Pickpocket someone, give him money and get it back, be sure to save a lot in case you get noticed.
Smithing, smithing is pretty easy to level, buy or mine iron ore or ingots and leather strips and make iron daggers. Just wait and buy the stuff again. A recent update made it harder to level up smithing but it still works.
I also advice to choose one of the first three standing stones, they give you a boost so you level up faster.
There is a glitch in the beginning of the game. After you've got your loadout, you have to sneak past a bear or kill him. Just attack the guy you need to follow and sneak behind him. This way you can level your magic, fighting and sneaking skills. (Don't know if this got patched or not).