New Custom Game Mode Idea

There are a lot of free champs that I still haven't played yet that come out on the free rotation. Because I want to play them, but not get called a feeder if I do poorly for not knowing how some abilities work, I was wondering if League could have a custom game mode where you spawn at level 6. Also, there could be a reset button for abilities to try multiple combos (e.g. Leblanc ult combos). This would definitely promote diversity to try out new champs, and practice hard to do mechanics (Riven wall jump). Would appreciate it if even if this is simply addressed by Riot.