Hey there, Latios! Welcome to the PokeCommunity! Glad to see an older member join in this amazing community! If you're looking for someone to battle or trade with, you should definitely go visit the Wi-Fi Center. It's the place where you can meet up with a lot of PC members who are also looking for a quick battle or trade! Also, there are some battle tournaments as well, so you should definitely check that out!
Anyways, if you have any questions, feel free to ask a staff member. Read the rules and the FAQ when you get the chance. Most importantly, have fun! See ya around! :)