Whether you need a visa or not to come to Finland depends on what country you are coming from, as well as how long you are staying for. You should check this as far in advance as possible.
If you plan to live in Finland for an extended period of time, a visa on its own may not cover you for this. Therefore you need to be clear whether you are applying for a visa or a residence permit .
EU nationals are able to enter and work in Finland for an unlimited period of time, but must apply for a residence permit if staying for longer than three months. As Finland is a signatory to the Schengen Agreement, Schengen nationals moving or travelling from another Schengen country do not need to show their passports or national ID cards to enter.
Nationals from the USA, Canada and Australia can stay in the country for up to 90 days within a 180 day period without a visa. However, they are not allowed to take up paid work during this three month period, and they may have to show a return ticket and provide evidence of sufficient finances to cover their stay in Finland. Citizens from all other countries are advised to contact the Finnish embassy in their country to check the visa requirements for visiting Finland.
Living in Finland requires you to obtain a residence permit from the regional government office, embassy or online . In general, any stay that lasts longer than three months, or is in connection with studying or working in Finland, will require a residence and/or work permit.