Yasuo isnt a difficult as some people may lead you to believe, but this doesnt mean you should take him into ranked on your first day! He does take practice but you will get there! I have 70k Champion Mastery Points with Yasuo, so that makes him my most played champion by over 50k Mastery Points but this doesnt mean that i dont still make mistakes; this build has helped me carry games and make huge comebacks, and also this build will enable you to duel literally everyone, the lifesteal and the armour pen make you unstoppable in 1v1 situations if you remember to use your W and E correctly.

Be very aware of creeps in lane that you can dash to
Try not to E onto champions to initiate as its best to save that to finish
Your Windwall can be a literal lifesaver, try to play all your fights around that
Dont Forget that youre a complete glass cannon and with the correct amount of CC youre a very dead Samurai

Once you get your first 2 items (Statikk Shiv and Berserker Greaves) Farmimg becomes flawless, you will one shot waves with the prock from your statikk shiv, but in the early game where CS is the most important, Farm using your Q, it has good range and good early damage meaning you wont miss CS, also it means that you will stack your Q and be able to harass and zone your enemy opponent with your tornado.