I need new champs to play as.
I just need new champs to play as in each role. I have a low winrate with my current champs.
Champs I play as in each role
Top=
Jungle=
Mid=
ADC (Not often)=
Support (Not often)=

I just need new champs to play as in each role. I have a low winrate with my current champs.
Champs I play as in each role
Top=
Jungle=
Mid=
ADC (Not often)=
Support (Not often)=

Id recommend narrowing that down to more consistent champions. Top
Jungle
Mid
or
adc
or
and support
. Keep in mind all of these are not the most consistent champs in the game but they are the most consistent out of your selection.
You don't need new champs, you need to narrow down your roles that you play and get the champs in those roles to 2-3 each. Instead of 4-6. Why do you think that one trick ponies climb so fast once they've learned the game itself? Because they master the mechanics, get everything nearly perfect, for 1 single champion. If they have general game knowledge to match, boom, they can compete with challenger players as that one champ, but would probably be somewhere in the range of mid-high diamond tier with anyone else, potentially lower depending on the difficulty of the champion.
However, if you really want to learn new champions, I suggest Kled and Fiora for top lane. They're both fairly easy and very strong, and can carry quite hard. Kled also is the only top lane champion with a win rate that's disproportionately high for his pick rate.