You chose the right time to arrive, just before the winter
Summer jobs are advertised as early as in March, but winter jobs ?? Perhaps you can throw snow from the roofs of buildings, also black labour of this type is available, but of course no insurence, nothing. A bit dangerous to say the least.
Finland seem to be the choice for many, as social system "keeps" these type of immigrants on benefits, not encouraging them to work at all, just sit at home and draw the unemployment benefits, once entitled for it.
The will put on the socalled Integration Program, which is to enroll you to school studying Finnish language, places are not enough, after that they dont help you at all, just say check on the website for work.
How will you live till you get yourself established here ??? Where will you stay? Your only option is to find someone to share a matchbox size home.