Working while studying
Working part-time while studying might be an option to finance your studies. Studying does not exclude the possibility of taking a part-time job in the evenings, over the weekends and during holidays.
It may be difficult to find employment in Finland, especially if you do not speak Finnish. Practically nobody speaks Finnish outside Finland. Finnish is a difficult language that is totally unrelated to the Indo-European languages spoken by the rest of Europe. That's why English is the third unofficial language of Finland. You can definitely get by if you only know English.
That said, it's still a good idea to learn some Finnish. It will help you connect – and it improves your chances of finding a job in Finland. Even a phrase or two will make a difference, as Finns really appreciate the effort. There is a self-help tool for initial steps towards this unique challenge: UUNO – Finnish language learning material.
Note: Finnish labour market is very law-abiding and working unofficially and being paid "under the table" is strictly forbidden. Employers cannot take you as an unofficial labourer due to risking their business license.