NAGACE, I'll tell you how.
Firstly, welcome to the Pit boards!
Next, like others have said above, please try and concentrate on the basics first.
The best thing to do, to get good with arrows, is go into custom stage builder, and put a sandbag down, then learn basic arrows. Shorthop shoot them, shoot them from different angles, etc. It builds your arrow game and after a while you'll get used to it. Arrow looping isn't useless in my opinion, notice how many I hit with and/or pressured him with into doing different things.
Wings of Icarus, (WoI) have VERY high priority. So, if you time it right, then you can cancel out attacks. then punish accordingly. This is the reason I input it into my game. I WoI and cancel something out, or if I don't do it I don't really get hit. It's a safe way to try and build damage/keep away from your opponent.
But something you're going to have to get down, first, is learning to camp. I don't care what ANYONE says about Pit, camping is THE single best strategy that you can do with Pit. The reason being is because if I hit you with an arrow, and then another, etc... it aggravates and frustrates your opponent. When they get aggravated, they normally rush you, as this is first instinct. This is when you switch up, but just for a second. As soon as you notice an increased amount of aggression, start grabbing alot! Just sheild their approach, and grab. This gets them even more frustrated. After that, just go back to camping. It works. The only character that can outcamp Pit is Toon Link. Wario is arguable but you can still spam arrows against him.