I don't recommend ad assassins in solo Q unless you understand how to solo Q.

I highly recommend nuke champs or ap assassins, like Katarina, Ahri, Veigar, Syndra, etc..

For top lane I recommend bullies or hard counters like Ryze, Lissandra, Riven, Jarvan IV, Irelia, etc.. Usually you want either waveclear or 1v1 dominance; if you lack either then you should always take teleport.

For junglers pick mobility champs who are good at diving and exploiting mistakes. This could be Rammus, Hecarim, Yi, Volibear, etc.

ADCs are all about knowing mechanics and solo Q to carry well.

Supports are actually better in solo Q (in my opinion) if you aren't proficient in ADC. You can always go unconventional supports like Heimerdinger, Leblanc, Annie, etc because they are cheese. As long as you build sightstone and make use of that snowballing you're fine.


Really picking "main" champions depends on your knowledge, skill, and overview of solo Q. If you do not know how to carry Solo Q then you are very limited to just raw mechanics, and in that case it is best to go top, mid, or support.

are you more interested in having fun or climbing ranked? if you are more intereste din climbing you should learn all the champions to the degree of knowing thiers skills and how they can be used before you even play ranked.

if just for fun play things until you find wht you like.

I want to have fun. But it's much more fun to win. I don't like losing all the time, which happens to be the case lately.

Play Riven.

Lee

He already has #1 lee jsp aka allsunsdawn aka plat 5 more like plat 4 5ever helping him

thresh or nami or jinx

Try out as many champions as you can
Find one that you don't think you'll ever get bored of
Main that champ and have fun