Ignore the toxicity for now, honestly. Focus on agents with hard crowd control or healing zones. You want abilities that mitigate incoming damage or lock down chokepoints because that is how you actually save teammates. I would suggest looking at skills that provide a refresh rate or a shield boost. Be careful not to waste your utility on solo plays; save those charges for when your team is pushing a site. If your connection is laggy, make sure you are wired in via an Ethernet Cable Cat8 10Gbps 2000MHz rather than using wifi, as that jitter might be the real reason your timing is off. Prioritize defensive stalling abilities over offense for now, just learn the maps and keep your teammates alive by blocking sightlines. Its a grind, but you will get there.