So you already wanna play 
Well then you need ~2-3 more picks to focus on learning/improving with Then you can branch out into more as you have a feel for the jungle in it's current state. Allow me to make some suggestions
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Don't learn
, he's banned way too much to be reliable
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Do be able to pick at least one AP and AD, as well as cover different roles. Example Vi is an AD Diver that usually builds bruiser to be able to Ult-stuff carries. So a Frontliner, Assassin, Bodyguard/Peels, Split pusher, full tank. These are all things that can be done from the jungle.
Frontline:
Warwick is strong right now, His route is safe and easy to learn and he teaches good habits with gank routes and objective control
Not as popular as he has been but by no means weak. has the ability to crush enemy tanks/juggernauts
Amazing at starting fights, and notably on the short list of Potentially high AP damage from the jungle.
Assassin:
Elise is probably the best early game ganker right now
Don't. She's good yes.... Well it's likely you'd end up learning "Nidalee" not "Jungling"
He does his job well, fun
Peels for carries
Solid early game, but unless unbelievably fed diving onto carries is unreasonable, But an Execute, atkspeed slow and the kick allow him to keep non-Olaf's off the goods
Shields, Roots, Daisy's knock up even breaking enemy vision with brush, Not to mention Ardent Censor, Athene's and of course Redemption is Staple for the lanky tree. But also is so different from other junglers and really encourages good Macro play.
Split push ((though all 3 of these guys can clean up teamfights under the right conditions, splitting is more 'a totally viable option against comps like Malph-Yasuo, or Gragas/Darius/Lulu/Cait where you just don't wanna 5v5 if at all possible))
A good Yi can climb from wood5 to Gold1 over and over, much less consistent above low gold But an exellent tool for climbing initially
Also tilts people, good early strong counterjungle can so silly lvl3 cheese routes with exp quint, AP or AD flexibility
decent ganks, eventually unstoppable. Great in lower leagues where many teams refuse to listen to the one poor soul who knows how to close out a game.
Tanks
Kinda strong, plenty of CC and hard to kill
Goes where he pleases, Underrated right now IMO
All around good right now, Ult is great damage is solid for a CC machine.
Take picks but do try to be diverse, if all you can play is AD fighters you'll miss out on potentially strong team synergy like Jarvan-Orianna or Ivern-melee badass top (free gap closer? extra shield with a slow? It comes with an AS steroid too?! and the Heals... Renekton going to town!)