Everybody needs to live somewhere. If you got to that part, you probably have some place to stay and sleep temporarily, but you need to get your own place as fast as possible, both to save money and to ensure you have a permanent address.
If you have just moved to Finland, your only option is probably renting an apartment, rather than buying an apartment or a house. Finland offers ridiculously low mortgage rates, but you need to have at least 10-20% of the price as a downpayment on hand, which is going to be a pretty significant sum (two room apartments in Vaasa cost 50,000-250,000€ depending on location, area, and building age and condition; you probably want to look at something not cheaper than average). And I doubt a bank will give a mortgage to someone who has literally yesterday arrived to Finland. Well, I don’t know, maybe they will, but I haven’t tried.
Renting, on the other hand, is something you can do right away, with much lesser initial spendings. There are some countries where renting an apartment is quite difficult in general (I’ve heard Sweden has some rather weird regulations in that area, for example), but Finland isn’t really particularly bad. Of course if you’re looking for the absolute cheapest price, or want to live in a highly desirable area, or possibly coming here in a bad time of year (particularly when the university students are looking for apartments) it would be more difficult, but still hardly impossible.
There are two basic options for renting an apartment: from a private person, or from a housing company. You can find better prices and more interesting offers from private people. And in buildings belonging to housing companies there is often rather high tenant turnover rate, and the tenants themselves will likely be poorer people. This is by no means certain, however, and furthermore renting from a housing company is easier, and they will usually demand a smaller security deposit.
Personally, I went with the housing company option. I’ve been living in an apartment rented in this way for over two months now, and I’m quite happy with it. My apartment block has decidedly an immigrant background; less than half of tenant names are Finnish. But this is not a ghetto or anything — the house is exactly as nice as every other Finnish house is. And I’m an immigrant myself and in general I find it quite distasteful when the people who are immigrants themselves shun other immigrants because of their background or skin color or anything. The location is also nice, 3 km away from the city center, and I’m not planning to move away anytime soon.