Just pick metaknight, spam down smash, and mach tornado, and juggle them if they’re above you with up air
EDIT:
Alternatively, look up a Character with an ez chaingrab like Falco or ddd, and frustrate the hell out of everyone there.
I’d say pick ice climbers and learn their chaingrab, but you likely don’t have a copy of brawl I’m assuming and so you can’t practice it. Their chaingrab is a bit harder to do and requires some actual practice, though it’s a million times more effective, and just far more frustrating to deal with. if you ever wanted to make an inexperienced opponent cry, and lose all motivation to keep playing, just chaingrab them to hell and back with ice climbers