Jungling or natural creeping (shortened, nc, usually used in Dota 1) is one of the most important things to do. Jungling give you additional gold and experience. Basically, jugling is more suitable for carry hero due to its advantage when late game.
Not all heroes are suitable for early jungling. Usually heroes that can summon units like Nature Prophet, Lycan and so on. Besides that, hero with a special spells like life steal, convert units or regen also perform well during early jungling.
To play well in Dota 2, you have to practice a lot. When you have master the basic skills such as creep stacking or pulling creeps, you can combine both skills during jungling. Good luck! :)