Leveling 1-30 (Coop vs Ai/Normal/Draft Queues) Review
Going to come out and say it: Leveling in ALL queue types is a horrible experience.
Coop vi AI
The least toxic is Coop vi Ai, but that's because actual new players are forced to play this game mode to try and learn without being verbally assaulted. But even still, you get some players who harass because you died to a bot, and they generally want you to quit the game or uninstall. This queue is a place of learning, if you can easily kill the bots then do it, but don't get mad at people trying to learn because you want to level an account fast.
Normal Queue
This one is mixed between complete one sided games and super toxic players. I've had a few games where the other team rolled us hard, but they didn't shit talk in all chat, they didn't spam laugh on your dead body, and in a few cases, they actually gave advice. But then you get the players who had an account banned for being toxic leveling up again. They non-stop verbally harass you about every "mistake" (in quotes because you don't even know what you did wrong) you make. The one sided games are annoying, but the toxic players are what make it horrible.
**Draft Queue **
Wow. What do I even say. You would need to see a doctor after playing a few games PRE 30 in this queue, because your sodium levels would be critical. This queue is full of players who had their accounts banned for being toxic and are re-making them. Holy crap this queue is toxic. It can be a 4 vs 5, 3 vs 5, 2 vs 5, it doesn't matter. You need to be ready for a full on verbal assault over all chat (HIGHLY RECOMMEND KEEPING IT OFF!). They are going to rip into everything you do, point out all the mistakes, laugh at your plays, call you everything from a dumb monkey to a retarded pig, and then laugh on your dead body for 5 hours after. There is a reason their main account got banned, and they clearly haven't changed at all. I want to just shit talk back to them, call them the same stupid names... but it's pointless, and I don't want to be banned.

9/10 times if you see these champions of the other team, it's not just going to be a fight of 5 champions vs 5 champions, it's going to be a war on two fronts; the second being your eyes and ears from all the crap they throw at you. THIS IS MENTAL TORTURE TO PLAY FOR 20 MINUTES.
TL;DR
Trying to level with anything but bots to level 30 is super toxic and makes me want to quit the game 5m into it. Lower level queues are full on previous banned toxic players. HOWEVER, you do find people who are nice. Players who even while crashing you say "gg" and "wp" instead of calling you names, but they are sadly a minority.
To the toxic players, try some happiness in your all salt diet. You may find it's more enjoyable to compliment someone instead of trying to hurt their feelings.
To the non-toxic players and people who simple don't type want to might want to say, thank you. Thanks for not calling me trash in all chat, thanks for not laughing on my body, thanks for making the game, even if it's completely one sided, not feel like a jail with a 20m sentence.