Help me pick my main

I have been playing league for a good three years. I mostly play it for fun. However, I want to play a lot of ranked next season and hit a high rank. I want to pick a lane and a few different champions with different play styles for that lane. So I can work with my team to make a good team comp

Right now I play mid with Azir, Ekko, Zed and Ahri. But I wanna have different type of champions (ap/ad, burst, sustain, early/late game, tank/assasin) and that kind of stuff. I think top is what I want to play but im open to suggestions as long as its not support. I want to play a hard champ that takes time to master but once you get them down theyre strong and can pull off 1v2s or 1v3s easily. (azir, anivia, swain, maokai, fiora, etc...)

I already play nasus, vladimir, poppy and darius, fiora is my next consideration. I would wanna learn rengar, talon, viktor, orianna, galio, jax and shen give me every bit of advice you have and Keep in mind im only silver 5 at the moment, so any advice would be good.