Hello there, JonathanLung and welcome aboard! Glad you found your way here in PC, you wouldn't really regret joining as you can do pretty much a lot of things here. I've also been a Pokemon fan ever since I was a kid so I believe it was a decade ago, if you recall all of it, it brings back a lot of great memories from my childhood days till then! I think you should be really proud that you've sticked to the whole game and all until today, I mean it's a feeling of achievement and you should be proud of that! :D
Anyway, my fellow members already mentioned the places that you'd probably visit. So I really hope you enjoy our CBC section, if you still haven't like explored it yet, PC actually has it's own PO server. You'll be able to find some of our PC members there whom you'll have a battle with and possibly become your friends as well! You could always ask them if you need any advice or tips when it comes to battling! I'm not good at it, so I'll pass. :3
What do you mean by the modding/game creation? I suppose what you meant was ROM-hacking or perhaps game developing? Well, with whatever that may be, PC has it all! And yes, PC it's known for it's creative works and stuff throughout the web! PC is really huge, so it might take time to adjust and it's really confusing at first, but as you keep on exploring, you will eventually get used to it! ^^:;
And don't worry, if you ever have any questions, you can always ask me for help! Fee; free to send me a message and I'll try to reply as soon as possible! Have a great time here and enjoy battling~