Assasin role

Hey everyone, Ive been playing assasin champions lately but I'm starting to realise I dont really know how to play as an assasin. Each time I end up going along with what my team asks (which is to group and fight) I end up being dead weight cause they just focus me and I die, or I dont see a way in the teamfight and my team starts getting annoyed with me still living.. Something else ive been trying is to splitpush but then I run into the problem that my team is outnumbered and gets wrecked before I get a wave to a tower. Can someone explain, or link me a video that explains what the role of an assasin is in a team. I really enjoy playing Ahri and Akali but yea, the way fights go it makes me wonder if I'm doing things right. Any help is much appriciated, even if I dont follow up on your comment!
Report as:
Offensive Spam Harassment Incorrect Board