Language
Finnish is notoriously complex, but even a few basic phrases go a long way and are appreciated by locals.
Basic Finnish helps with daily life, job hunting, and integrating into local culture. Many Finns appreciate any effort to learn the language.
Duolingo has a Finnish course for absolute beginners. The Finnish Immigration Service (Migri) and municipalities often offer free integration language courses. In some situations (long-term residents on certain permits), integration training including language education may be required. The Yle Uutiset Selkosuomeksi (news in easy Finnish) is great for practice.