Finnish is not necessarily hard, but it's definitely different.
Your best option is to forget all you know about grammar structures etc. from other languages and completely start over. You will need suffixes, lots of suffixes, there are no prepositions or articles.
It's easy to pronounce though once you get the hang of it, because the pronunciation of each letter is always the same.
And don't fear the grammatical cases. True, there's a fuckton of them, but once you start to understand how they work it gets easier.
Also, compound words, learn them well, it gets fucking irritating when teenagers fuck them up constantly when it's not really that hard ("can you put an adjective between them? No? Bingo! You have a compound word!")