He is really good.
I can just lost off what trouble new Yasuos have and see if I hit or miss your prob.
Practice you're E
Practice it utilizes you feel good on it
Never be ashamed if you want to practice to be, You are stronger today than Yesterday.
You can dash through Krugs and Gromp and raptors.
You can Auto before ult
Make sure you get the latest Runes and masteries. (3 quints 9 reds attackspeed on both. Yellows get armor or scaling health. )
For Masteries use fervor
Get vampirism, and that bloody tooth lane phase and snowballing becomes way easier.
It's k to get 2 dorans blades
Rush PD
Get IE
Rest is Up to you.
Also personal thing here (Shiv increases your damage by 200-300 before it didn't you can use both PD SHIV with IE I got a penta with it it's on op.gg)
Next.
Start q against melee always.
If you auto your target more than dash you get Lifesteal and lots of damage off. I've seen New Yasuos make the absurdly deashy deashy thing and it doesn't help a lot the dash doesn't make a Yasuo.
The player Makes the Yasuo.
Next.
Look up Yasuo combos on Yt, and Redmercy, Yassuo, and that one reddit video is good.
If you use R and your target's next on turret range your ult will place you outside turret Range quite generously.
Nado can't dodge, it's first hit applies on hit.
Q won't get minion aggro if. You hit a minion before a champion.
You can E-Q before you ult and your E-Q will end on top if your Ult location videos will clarify easier.
Yasuo can solo rift herald after PD
Windwall doesn't block lasers except Viktor's ground laser.
Jesus that's all I know off the top of my head.