Hi! Just wanted to give you a quick snippet of info that may be helpful to you.
Top laners are typically Brawlers or Tanky individuals.
(Think Naut, Dr.Mundo, Nasus, etc.)
What does that mean for you?
Well, your team is going to want you to be tanky, and they're going to want you to bring some damage and some HP to the fight. The best way to do this is to play Champions that are known as fighters or brawlers, and just learn to play them. Take some time and devote a game or two a day to learning one and you'll be well on your way to winning team fights (though, remember, there are many variables at play in team fights!)
Champions you may want to consider:

Personally, I recommend starting with an easy(er) Champion, that is somewhat snowbally, to learn.
So take Riven
or Nasus
(Snowballs hard late game). Wu Kong
(though I see you don't like Wu) or Trundle
would be good options when you're learning as well.
I just posted pretty much any Champion that would be generally ACCEPTABLE Top in the current Meta. If it's not listed, it's (probably) not viable.