Satakunnan monikulttuuriyhdistys (The Multicultural Association of Satakunta) organize open finnish language studies. Here you can find info about their courses and conversation groups.

https://monikulttuuriyhdistys.fi/en/learn-languages/

Satakunnan monikulttuuriyhdistys has written Työelämän ABC (working life ABC) guidebook (also found in internet).

https://monikulttuuriyhdistys.fi/tyoelaman-abc-2/

From this book you can also find useful information and links where you can study Finnish. Also there you can find useful links to study Finnish online. Information is in Finnish but you can use Google translation to translate it to your native language.

https://monikulttuuriyhdistys.fi/suomen-kielen-oppiminen/

At this guidebook there are listed some organizations and schools where you can study finnish. To study finnish in school you first have to apply to become a student.

Also from the library you can borrow some books to study finnish. Ask more information from library workers. Also library has some e-books you can borrow to study languages. You need library card to use these services. You can get library card for free from your nearest library (in Pori: Porin pääkirjasto, Gallen-Kallelankatu 12, 28101 Pori). Here is a link to library e-book language course materials:

https://promentor.kirjastokurssit.fi/satakirjastot/home

Also Porin työväenopisto have some finnish courses but because of the coming summer these courses are finnish already. Next season will start in autumn so you can check what kind of courses they have at the end of summer. Here is a link to their webpage:

https://uusi.opistopalvelut.fi/pori/en/?q=finnish&page=1