New player looking for help picking champs

Hey reddit, so I've been leveling up (lvl 20 atm) and have been trying out as many champs as I can to get a feel for the game and how they play. But as I draw closer to 30 I'm feeling more and more like I should work on refining my champion pool.

Thus far I've found I like ranged characters much more than melee ones (exception for Alistair when I play support) I've got the most games played on Miss Fortune, Lux, and Caitlyn. So I'm wondering if there are any other champs like these that I should start practicing.

I typically play mid or bot lane since people seem to take top ASAP.

Any advice is greatly appreciated