regulation

To fly in Finland you need a valid license. Best would be an IPPI card but a recognised foreign license may do. Bring your logbook in any case. Insurance is mandatory, that is your glider should have insurance for any damage etc. caused by its pilot to third parties. Just like cars need everywhere. Of course you might want to take a health/travel insurance for yourself.
Gliders should be certified, but you do not want to fly one that isn't.
Hang- and paragliding is very much self-regulated in Finland, and we like to keep it that way!