I got a few champions, but I realized all of the ones I use are top, and I would like to go mid as I prefer soloing with Teemo, but every time I went mid with him I lost. I want a new champ and have saved up 4800 IP. Since which characters I like defines which I will get here is the list of my current champs:
I have a few more but I never use them. Any suggested characters? I'm thinking of 
and 
Please help. and thx in advance
lux
If you like Warwick and Cho then you would probably love Malzahar.
I've been playing AP Ezreal Mid for about a year now, and absolutely love it. Runeglave is helping a lot of people get into his AP Builds, so you could try that and see what you think.
It's worth pointing out that later this week that a lot of AP Items are going to be getting their stats shuffled, so it'll be hard to say who will be strong or weak then. The important thing will be to pick a champion based on what you like to do.
For me, I like long range, mobility, peeling for myself/allies, spamming spells, and lots of damage. I think for every champion I play I have to pick 4 and call that good. I prefer being helpful in team fights to getting picks most of the time as well. Being squishy normally doesn't bother me. Using that criteria, these are the champions I've enjoyed playing mid:
Champions that are fun for me to play, but I only play them occasionally (aka: not bad, but not my cup of tea):
The question becomes what do you like in a champion?
It depends on who sounds fun to you. It seems like you're newer to the game so I would suggest easier champs that you can learn on.
Mid is played a lot differently then top, because the lane is shorter and you can roam around most mid laners have a lot of burst or range.
Annie makes makes cs'ing real easy. Also has insane burst with her ultimate. She loses to people who outrange her.
Lux is best long range mid laner right now imo. She was the first mid laner I had success with. Ziggs plays similar to her though if he sounds more fun to you, but I think lux is easier. Both lose to assasins.
If you want something hard you can play an assasin: zed, talon, ahri, diana, ekko, fizz, yasuo, etc. These guys are weak-ish right now I'd go with mages.
If you want a full list of mid laners google "league of legends tier list". There's a guy who keeps a blog on the best champs for all roles.
Teemo is a sub-par mid champ by the way, he's only good because he counters most top laners. A new mid champ will really help you out.
TL;DR: Play Annie and Lux.
