What is determining my matches for my account and how can I hold my own.

Hello! Long story short. I got into league in college because of someone I knew.

Here is my question. My profile is level 17. And the match making is not making sense to me. I am playing blind pick at the moment. From a game mechanic, it seems to be good way at learning champions. But, and here is my issue. I'm going against players who are much higher than me in profile level. I looked at some at my worst games and with the other team. I'm fighting 25-30 at times. At times in gameplay, I can predict if they are higher profile level or not by how difficult they are. Am I suppose to be fighting players at these higher profile levels? I know that the match making is supposed to based on skill, but the disadvantage is glaring me in the face.

If I have to step up my game, fair enough. But I don't quite know how to go about it. I've started to use builds, even if I can't use them at the full potential and I started to use items sets preloaded in game. The only other thing I can do is learn the champions but that is all I can think of. Is the disadvantage something I will have to just struggle through or is there something I can do that I am missing? I am using runes and masteries too.

Some thoughts and hints would be awesome.