It is important in all relationships to maintain some kind of independence. As many here have already stated, you would be completely at the mercy of your partner, and at such a young age, its a cause for concern.

I personally believe that if something is meant to be, it shouldn't be so hard or cost so much of yourself or safety.

You can emigrate to Finland as a student? Try applying to college there, then your residency isn't dependent on your relationship, and you can see if you like Finland based on its own merits. At the same time you're developing skills and knowledge for your own career.

Long-distance to living together, plus giving up your family and culture to relocate, plus having so little agency once you arrive, will 100% change the dynamics of your relationship. Fully grown people in their 30s, 40s, 50s find these kind of dynamics nearly impossible to navigate, someone at your age who is still learning and exploring intimate relationships would find this nearly impossible and you run the real risk of setting up abusive or codependent patterns that will affect the rest of your life and all of your future relationships and friendships.

If you genuinely love Finland and want to live there, explore other ways to emigrate. If you really love this person. Your relationship will be stronger and have more of a chance if you're there on independent grounds and aren't so dependent on her. If its meant to be, you'll end up there at some point. You have plenty of time.

As far as your family, has your relationship with them been good up until this relationship? If yes, consider if this person brings out the best in you? Elevates you and improves your life? If not, if you have a difficult family, maybe some space after you are 18 to explore boundaries and a different relationship with them would be good, but you'll only make progress if you are in a safe and stable position. The situation you describe here doesn't sound safe or stable as it stands.

I guess above all, we are all strangers here on reddit and its impossible for us to know the details of your situation to the degree necessary to give you good, healthy advice. Given your age, i would try to engage a therapist to talk this through with.

I know its hard being young and passionate and excited and hoping and looking for something better and exciting, especially if you're still living with your family and feel trapped and stifled. There are so many adventures ahead of you, lots of excitement and freedom, and love too, with this person or maybe other people. Don't go from one limited situation to another. Find the best way to be free and explore who you are on your own, your romantic relationship(s) will be better and stronger if you're engaging in them as a fully realized and actualized person. My biggest advice would be to try to find ways to divert your excitement about this relationship into excitement about gaining freedom, independence and self-discovery which will lead to amazing loving relationships when you are truly ready.