it starts from "easiest" to hardest to master and i gave a "aint readin allat" explanation on every agent
duelist:
1-Reyna (you cant blind your teammates and just push wherever you want as long as you kill and dismiss/heal, aimlab is free btw)
2-phoenix (not like its pretty easy but ofc its easier than the ones below him)
3-jett (not easy also but the other ones are a pain in the ass)
4-yoru (can diff most other duelists on the right hands but it depends a lot on how enemies react to your util and how you adapt it, making it hard to use for all aim no brain duelists, and its a hell if you dont use him on specific maps)
5-raze (most razes dont even use their satchels properly and cant hit an ult/nade LMAO)
6-neon (all her util is hard to use properly ngl, specially her ult which is ass if you dont have a well trained tracking and cracked movement on high ranks)
sentinel:
1-chamber (aimlab is free)
2-sage (just learn how to place the wall bro its not that hard)
3-killjoy (watch set-up tutorials)
4-cypher (watch set-up tutorials and learn how to flank)
initiator:
1-gekko (your flash doesnt flash teammates, ez big ass molly, and the ult its a more op skye dog, wingman just walks straight no way you throw it wrong)
2-fade (prowlers aren´t hard to move and detect mfers, the eyeball can be thrown from wherever you want to wherever you want and the succ and ult arent very hard to master)
3-kay/o (if you dont flash or molly your teammates you´re fine)
4-skye (has the hardest flashes but the rest kinda ez)
5-sova (hard, not gonna elaborate, only one who can ace his own team on the right/wrong hands, legend says even sova mains are still trying to master the fucking ult till this days)
6-breach (you can be a breach main and still mess up all of the util).
controller: (there isnt even one on this category who is easy to use btw)
1-viper (just watch a tutorial there is thousands out there, and also comm when your wall or orb is fading away)
2-brimstone (easiest one in terms of throwing smokes, but you will spend hours watching molly tutorials tho)
3-harbor (hard, but not as hell)
4-astra (if you dont comm dont pick it bozo)
5-omen (try not to blind your teammates or mess up the one way or kys with a braindead tp/ult once per map challenge 99% impossible even if you marved or mako)