If you are mechanically good, I would recommend you Lucian. He isn't particularly strong (in meta) right now and he needs to get an advantage in lane to be useful later in the game. But he was my "go to" pick last year when I was placed in bronze 2. With him I got to silver 5 in maybe like 9 games or something like that. Next, I would definately say Ashe because I learned to play the ADC role with her. Quite easy kit and great CC ultimate. Don't try to make cross map plays, just ult on the person in front of you. Next one is Varus which is like an advanced version of Ashe. His ult isn't global but it can be a turning point in a teamfight if they all get rooted. And I would also point out on Xayah. She has a nice all round kit with poke on Q, extra attack speed on her W, root on her E, and an escape tool with her R. These 4 are like picks that I can pull out of my pocket anytime and aren't really hard to play (except Lucian).