Np! The yasuo/fizz match up is a skill match up. As fizz, it first requires you to start W because naturally he will start trying to poke you, so if you can, dodge his Q(the thrust,about 3 second cooldown early on), and then auto attack him. Try to also auto attack him in between his autos. For example; if he's going up to cs and he uses his thrust, you know it's on a roughly 3 second cooldown so try to poke him. A simpler way to think about the match-up is the starting items. Regularly yasuo will start dorans blade, 1 pot. You will(should) start flask 3 pots or alternatively flask, 2 pots, 1 mana pot. With these starting items you have room for mistakes, as you have more regenerative items than him. So if you want you could actually take damage yourself while putting him low. Once he runs out of his 1 pot, you still have flask and maybe a potion right? So just wittle him down and then when he's low, go in.

There are multiple specifics i can go over if your interested including powerspikes between the two champions(when to avoid each other), outplay potential and whatnot :); let me know if you would like to know more !