From the app click on their name and you’ll see their profile with add as friend, message and the last one has 3 periods. (…) click on it and it has report and block.

I let people send hate-mail, since now on PS you can report them for harassment and its a suspension.

I have never seen a PvP environment that wasn't poisonous as hell tbh and the only thing I can recommend is avoiding PvP/competitive in entirety. Think about the kind of person that habitually seeks out opportunities to engage in PvP environments. They've got chips on their shoulders and axes to grind and they don't typically show up just to have a good time, they show up to make sure everyone else is having a bad time and they want everyone to know it was THEM who made everybody have a bad time, hence the prevalence of PvP-focused streamers. "Look at me. I'm powerful enough to hurt you, to ruin your game time. Pay attention to me. Feed my ego." The best response to this is to leave the festering messes that are PvP environments to stew in their own poisons. They get sick of each other soon enough. I mean, who wouldn't? Don't feed those beasts, when they've got nobody to eat but each other they soon decide they'd rather go hungry.

play better, ignore messages.

Just dont look at it or get better so people stop messaging you

I don't think there is a way to block incoming messages. And if people don't message you they teabag you, sadly there is no way around toxicity in games. The best way to deal with it is to learn how to live with toxicity. Don't pay attention to these toxic people. Them being toxic only means they've got even bigger issues.