Hi , im FendronP , a friendly summoner from EUNE who just wants to make friends and help others :) , now that i introduced myself I am gonna help you with this awesome guide

Pros
+Fast clear time
+Strong dueling and ganker , that is even better after 6
+Enemies will think that you are going top or mid because you are an off-meta
Cons
-Ganks may not work that well pre 6
-Not a sustain that the most junglers have

Max WSeastone Trident because it's your main source of damage when you are clearing the jungle, skirmishing the enemies(small 1v1 in the jungle),teamfight potential ,assasinations . Next you max out your EPlayful / Trickster because it's your main Dodge/Escape/Engage . Max Q Urchin Strike last because it was nerfed badly in the 5.2 Patch and if the target is not in the range of it it doesn't do any damage , and you need some items to do damage with it , so maxing it last would be a good idea.
Ultimate MUST be maxed first at levels 6 , 11 , 16 like all the ultimates.

We take the maestries above in 21 in offensive Offensive for proped assasination , damage , skirmishes and clear speed. And take 9 in Defensive for jungle surviving , DPS to Neutral camps and , overall tankiness to survive teamfights and skirmishes.

W is doing % health damage so you can fight , clear speed and assasinate like a few champions do , E is a great escape that almost no champions have , Q is a second escape tool which can be used to engage/disengage/juke an enemy , keep in mind that it also effects as sheen/lifesteal
Your combo as Fizz Hybrid/AD/AP should be R-E-Wait for E to land-Q - W -Start auto attacking and you just killed the enemy 1 hit , which only a few assasin can do so fizz is still that unique assasin that the player who plays it love and play him for what he really is . (R-E-Q-W)

Blue path:
First Clear:

Start Gromp and make sure to smite it before you auto, go to Blue next and then Red, smite Red and back to buy items.
Second Clear:

Kill raptor camp and Smite the big raptor for the buff to clear a potential ward. Gank after raptors.

Route 2

Red path

Start krugs and Smite it instantly to start the stun proc as quickly as possible, I am usually close to full health after that. Take Red after krugs then go over to your Blue. You can the take the Scuttle Crab in the river for vision and some free hp. if you have over 1/3 hp gank top if it is available or just back and buy items. NOTE: that route is a bit more difficult for new jungler's.

Second Clear

Go to raptors, kill all the little ones first and then Smite the big one for the buff. If you are low on hp kill the Scuttle Crab for hp and then gank mid.

You are the backline assasin , jump on that carry of their team , assasinate him with your combo and evrything gonna be alright :)

Fizz is an exceptional assasin , which can be played jungle and do very well , he counters tanks completly due to his Magical and Physical
he deals , even if your behind you still have a good assasination potential that is even more deadly for every member of their team.
Thanks for reading my first guide ,good luck in soloQ and have a wounderful day :)