So for starting a champ pool, how many champs should I look to have for each lane?
I'd say look to have 2-3 champions per role for 2-3 roles, maybe have 1-2 champions you can use to fill in the other roles. I have a similar problem where I'm constantly trying to trim down my champion pool in order to actually be able to play them well. I'd also recommend playing simpler champions; this way you can focus on your fundamentals instead of just wrestling trying to learn a champion that is way beyond your control.
Is it better to have meta picks, or picks you enjoy?
Picks you enjoy, definitely. Having the meta picks are nice, but the meta constantly shifts; if you pick a handful of champions that you master, you can play them in any meta and play them better than other players who are just picking up meta champions for the first time. Plus if you play champions you enjoy, instead of what's "OP" at the time, you'll stick with them longer even if they get nerfed. You definitely want to be aware of the meta, and sometimes a few of your picks might fall so far out of the meta that it becomes more effort than it's worth to play them, but that's why you have a few champions per role instead of just being a one-trick-pony. It's solo-q, everything is viable if you know how, and consistency pays off more than just riding some FOTM pick until they get nerfed.
Looking at your picks, you're playing some of the most complex champions in the game, so I'm not surprised when you say you're struggling with them. If you want to pick 1 or 2 of them and really master them, that's fine, but if you're looking to spread yourself out a bit more, here is my opinion:
Top: Irelia and Renekton are alright imo, just make sure you know how to play them in lane, when to pick them, etc (Renekton is more aggresive early). Lissandra is also very powerful, but playing mages top lane is very nuanced imo; again make sure you know how to play her.
Jungle: I've seen people have success on Skarner; Amumu I think has some sustain problems early, but aside from that he's good. I hear Evelynn has a lot of problems right now, she's sort of one of those examples of champions too far out of the meta, but if she gets buffed she'd be good still I think.
Mid: ....I'd say avoid all of these. Again, unless you really dedicate yourself to one or two of these picks, play someone a bit less complicated.
ADC: Ashe is okay, she suffers a bit in the damage department compared to a lot of ADCs but she is still underrated imo
Supp: Leona and Sona are good
Here's my pool in case you're interested; I'm focusing on mid, ADC, and Support.
Top: Malphite, Wukong (situational)
Jungle: Wukong, Vi, (will perhaps pick up Warwick after his rework)
Mid: Orianna, Annie, Kayle (still practicing, situational pick), Nidalee (situational) (will perhaps pick up Ryze after his rework)
ADC: Jinx, Caitlyn, Tristana (waiting till things pan out a bit more because she was just reworked)
Support: Janna, Braum, Sona (situational), (will perhaps pick up Taric after his rework)
Regarding Nidalee: You might be wondering why I'm recommending against you picking Nidalee (unless you want to dedicate a lot of time to solely playing her) when I have her in my champion pool. Basically, I'm a Nidalee main; I've probably played more games on Nidalee than any other champion, and I understand her just as well if not better than I understand any other champion (including the "simpler" ones) in the game, which is why I'm comfortable including her in my champion pool. That being said, she's still a situational pick, so I still seldom pick her for the mid lane; I wouldn't recommend picking her up unless you already have a good footing on her; better to pick a champion that you can play more often.
Even then, I'm not bringing her into the top lane, because I don't understand how she interacts in the top lane, and I personally don't think AP Nidalee, at least, has a place in the top lane (AD Nidalee is completely different, though I also think she's situational at best and awkward, but I don't play AD Nidalee so that opinion probably isn't worth a lot). Jungle Nidalee, imo, is a similar story; you see her snowball a lot in the early game, but even with that she tends to falls off later in the game because there's isn't much she can really contribute; Nidalee is a champion with no CC, AP Nidalee is super squishy, and in the jungle, she's under-fed until super late game where she can catch up in items. Nidalee is a champion that provides a bit of utility with the vision her traps provide and her heal/AS buff, but aside from that she only contributes damage, and, when behind (where she naturally is in jungle, compared to solo lanes), she doesn't really have the impact that a solo lane Nidalee would. AP Nidalee in mid lane is already very situational (no CC, high single target damage that's easy to dodge/miss, a bit of AoE burst if she has an opening to get into melee range), jungle is more-so because you're taking away a fighter/bruiser/tank type champion in your team composition in favor of a completely damage focused champion (this is why I think playing mages top lane is very nuanced; a couple such as Ryze or Swain can get away with it since they get pretty tanky, even Lulu because she has increased survivability with her shield and ult). Unless you have a team comp that's build around her, I really don't see her working out too often.
On top of this, I think Jungle Nidalee is one small nerf away from never being played again, assuming she doesn't just fall out of favor on her own. Kind of like how jungle Twisted Fate was super FOTM for a while, then devourer got nerfed and jungle was changed to prevent you from save-stating soft-leashing* too much and you never see TF jungle anymore; Twisted Fate didn't even get a direct nerf.
Overall the idea in picking champions is to pick a champion/practice a champion to the point where you don't have to think about what you're doing, all their mechanics become completely natural to you and you can focus your attention to how you're actually playing the game as a whole, instead of wrestling with a champion that's too complicated for you. Again, if you really want to dedicate yourself to a particular champion or two, go for it, and if you just want to practice mechanics or something on a very complex champion in custom/bot games or something, go for it, but I'd say stick to simple champions and get your fundamentals down first and foremost. Feel free to discuss with me if you disagree with something I said, I love talking about this stuff, lol
