We have in Helsinki this group called "Pääkaupunkiseudun Cosplay association" (http://pkscosplay.wordpress.com/)
. It's fairly big group of cosplayers in Helsinki, and we have meet ups in two to three times in a month at the same place every time (usually). You can just come there and you don't have to be a member. You can be the member if you want. It's free, and it's doesn't matter if you are from different country.
Age gap is around 16-27 I think, and most of members are around 19 years old. And everyone can speak English!
Usually when we have meet ups there is a random talking, eating food, some playing games/watching animes etc. And of course, if someone cosplay, there is a photoshoot too. Then we have these "anime all-nighters", picnics, cosplay workshops, gamenights etc. etc... It's super fun!
If you are interested more about this association, you can send me private message, and I will tell you more about "Pääkaupunkiseudun Cosplay association". (and sorry, I can't write English that well... OTL)