I've 8 wins in a row, I think it's enough to say I am somehow better than what my level says(?). I've not played with anyone on my friend list on those 8 wins and my record kills is 48. If it's necessary then I am 18 level player.
Then how I can make my games more challenging (To me)?
The people you play with are not decided strictly by your level. There is a hidden ranking system that you have a certain rank (colloquially known as normals MMR) on and the people you find in matches are close to your rank. Your rank goes up when you win games, and down when you lose games. If you win substantially more you lose on average your MMR will go up much more quickly than an average players and you will soon start playing against better people.
TLDR: just play more and if you keep winning you will soon be matched with better opponents, there is no shortcut AFAIK.
