It just takes a lot of time to really learn the game - don't get too frustrated. Especially when it comes to learning how to jungle.
Jungle can be an incredibly complicated position when it comes right down to it because every champion jungles slightly differently, and as far as ganking goes, that's always somewhat dependent on lanes and composition of the team or the enemy jungler.
When you gank, you're looking for lanes where the enemy is over extended, doesn't have wards, and you're looking to take a path that puts you probably behind them or surprises them, rather then running through an area that they have a lot of vision on you, giving them plenty of time to retreat. Bot lane is difficult to gank due to wards, but you can often ask bot if they know where/if bot lane is warded.
When you're going in for a gank, ping or IM to let you teammate know your intentions, always good. Helpful to let your team what your thoughts are, for example, you can say, "clearing red, then coming to gank mid" or something like that.
Hope this helps a little, and best of luck to you!
I don't personally jungle much or I would offer to play some games with you, but I play other lanes a bit if you have any more questions.