Fizz is an extremely good pick against the tank meta because of his ultimate : Chum the waters, which increases damage against the enemy who it hits by whole 20 percent which is 1/5 for 6 seconds it helps Fizz's main combo to burst down tanks in matters of seconds,he has extremely strong team fights and is basically always a decent pick.

How to survive early game

In laning phase on early levels , Fizz is one of the weakest champions you can pick,but on levels
2 and 3 you get a huge powerspike as you can start to poke enemy with your combo.Starting with flask will give you enough to survive early levels with ease. Although Fizz has a really hard time for first couple of levels on LVL 6 you get a huge powerspike that allows you to assasinate any enemy even if he has a huge gold lead.After you get to rush lichbane you do insane amount of damage even with your autos.

What to do when I have nothing to do on my lane?

Loosing or winning your own lane you basically still go on and do the same thing you ROAM a ton
this will get all other lanes ahead and will help you to win your own lane.You farm up a bit until you get fed if all your other lanes don't need help even if you're bit behind after you get 2-3 core items you still do a ton of damage

What do I do during team fights?

You go on to enemy's back line and completely destroy all their glass cannons and then just take care of their front lane with your team and you win team fights.Fizz can solo up to 5 enemies at once and still kill two or three and escape

Fizz scales extremely well late game you're able to two shot squshies.

FIZZ COMBO

1)Fizz's basic combo is to ult , q , w , e , w auto auto which gives you kill 99% of the time.

Tips & Tricks

When you Q you apply auto by just using Q if you w just before using your Q you apply W's DoT one extra time.

When you don't use the second part of your E then you do huge AoE damage and apply slow to your nearby enemy

Fizz is able to carry games by destroying other's team's damage dealers in seconds so at any point of the game you're able to carry.

You can escape 99% of the time which means never just give the kill without fight

As Fizz you're so mobile you can kill while running
Even if 5 enemies chase you,you can just ult the fastest one and E away and Q to monsters and minions you can always run away if you have mana !

JUST NEVER FORGET TO BUY MANA POTS ON EACH BACK ! GOOD LUCK AND HAVE FUN WITH FIZZ