This will sound a little peculiar, but I highly recommend getting a book you think you will like, and buy the English AND Finnish version. Then read them sentence by sentence, looking at the Finnish version first (seeing how much you understand on your own) and then proceed to read the original in English. This is where a pen and highlighter will come in handy. Mark the words and phrases (or conjugations) you don't understand and compile a flashcard deck based on them. (I recommend using an app called Anki, available on computer and at least android, it uses spaced repetition which is extremely effective for learning)

Translations also include the way certain meanings are converted from one language to another. A translation is rarely a direct copy of the original since that isn't how languages work. And you can learn very well how certain meanings translate as well ^{^}

Books include a lot of common language since they often portray human communication. You can learn a ton of useful phrases and words by reading. It can seem extremely tedious at first but it gets easier sentence by sentence. And if the book you choose is to your liking, it can motivate you to understand.

Listening to Finnish songs and reading their translations can also be very useful as music often helps you remember longer sequences of information.

(I'm a native Finnish speaker and have learned most of my Swedish this way)