Find your niche.
Final Fantasy! <3 I love those games, haha. My username actually came from one of that series' recurring characters, and I have to say that it's because I like the series so much that I did that. :D Maybe we can talk about it if you'd like to! I haven't played all games but I know a good amount about each, so a VM conversation will always be welcome.
Anyway, welcome to PC, Dangelitus! I'm glad that you liked our IRC people. :> I owe them for making such a great impression that made you want to register and test the waters here, too! I must say, the community is really friendly in general; hopefully you'll like this place a lot that you get to talk to a lot of friendly members. :3 If you keep an open mind and a positive outlook, then you'll see what I mean when I say we're friendly. :)
Like Megan said, don't worry too much about not being a native speaker. I'm not a native English speaker either, mind you, and I get a long just fine. n_n In fact, I could say I picked up a lot of things by posting in this place often, and it helped my grammar, spelling and whatnot improve a lot! So I'm sure if you stay active, you would slowly but surely speak (or write!) more fluently.
Megan and Wind Heart recommended good sections to visit. Trade Corner in particular would be the perfect place to look for a trading buddy for your Diamond! I know how frustrating it can be to have Pokémon that evolve through trading stuck in their secondary stage. :p If you need any forum-related help, don't be afraid to send a staff member a PM on their way, as long as it's about the section they handle. Have fun posting! ;D