League of Legends (LoL) Question: I wanna Buy a Jungler

Quinn seems good for you, has 5 abilities, high mobility, and on free rotation atm.

Best meta champions that are fairly easy to learn are gragas and graves. Gragas is really good in the meta as he is strong at all stages in the game and can carry fairly hard while being tanky

Graves is fairly easy mechanically and has a high amount of burst. He gets fairly tanky and has great scaling into the lategame.
Ultimately if you want to stick to the meta go for graves and gragas.
If you want carry junglers in the meta try out kha, he is very strong.
I am making a huge nocturne guide which will come out in a couple days and I believe this champion is kind of a dark horse jungler. He is fairly simply mechanically however has great potential to take over games even in higher elo( I am masters)

Feel free to ask any questions I will be happy to help!

Trundle ? He excels more at top but can also be good in jungle, due to his passive that gives sustain and Frozen Domain steroids, his ganks are quite underwhelming but his teamfight is strong especially you decide to ult that 1 full tank guy

I think you'd really click with Udyr then. He has quite a simple kit so you won't have to worry too much about skill order or whatnot. He's one of the fastest champions out there and can be impossible to kill (ugh honestly it's so annoying playing against him) and he gets objectives REALLY well.

His jungle sustain isn't bad at all due his Iron Mantle!

I would suggest Sejuani or Gragas because they are incredibly strong at the moment but they do not exactly have high mobility. They deal good damage considering how tanky they are and are quite easy to play. They can also easily clear the jungle and have a high amount of health left at the end of their clear allowing you to go for a gank. They have lots of crowd control as well so I'd say consider giving them a go.

I would also suggest Hecarim if you're a fan of AD bruisers.

Kindred comes to mind.