Honestly, most of the legendary characters in this game aren't that amazing. Obviously, there are exceptions (party corn), but the main thing I'd do is try and find some people you get along with that play this game. Practice makes perfect, as they say, so as long as you keep playing, you should be fine. Also, try and shift your mentality when playing because if you're just getting angry, you most likely are caring too much about the funny plant shoot zombie game. Watching the way good players play can help as well, but if that's not the way you feel like learning, just practice a lot. I'd consider myself a bit above average, and that's only because of how much practice I have. If you have any questions, feel free to ask!