I need some help

I am a returning player to league and I want to main jungle. I want to choose 3 main champions to ensure I grow as quickly as I can. I absolutely adore nidalee however it seems like she is no longer good in high elo. I don't want to be a flavor of the month junkie but I don't want to absolutely waste time on useless champions either. Can nidalee be effective, not in just low elo but high elo? Does nidalee hit a wall like say you can get diamond / masters but never challenger etc? Any advice on this as well as the champions I'm thinking of working hard on is greatly appreciated. Have a great day all! Considering the following champions:

1. Nidalee
2. Warwick
3. Khazix
4. Shaco

If you have any other suggestions for good jungles to learn please feel free to post them as well. Thank you so much!