I play fox, I go to most locals and pretty much any major tournament in the Netherlands(which comes down to syndicate) and plan on going to Heir 5.
If you don't have any experience playing melee you will be getting absolutely trashed by almost everyone you play against for at least half a year depending on your region, so don't get your hopes up because you have competitive experience elsewhere.
And don't go to tournaments to "do well". Go there to get bracket experience and play friendlies against people you don't see in your own region. Experience matters far more than a set win