What is the best way for a new player to learn the champions?

I'm a TFT player, but with the augment system they added in ARAM Mayhem my friends have convinced me to start playing. My issue is that I'm completely clueless on the vast majority of the champions. I spend the load screen and beginning of each game frantically trying to speed read my champ's abilities and passives to digest their kit... but some of them are so wordy it's impossible for my ADHD brain to absorb it all.

I know it's just ARAM and not considered a competitive mode, but I still want to improve and learn these characters quickly so I can stop griefing my team (and so my randoms can stop flaming me for being clueless.)

I found a youtube series that did 3 minutes videos on champs, but it's actually almost "too fast"... Half of the time I don't even understand what they're trying to explain, and a large portion of the content is geared towards how to lane with them and handle other parts of the summoner's rift map..

Is there a site or content creator that focuses on quick, easy to digest descriptions of champions and their abilities for beginners that are playing champions for the first or second time?