Hey Hannah, I swear we are just mirroring each others language paths here! I’m waiting to hear you start your Italian journey next 
If I can give a piece of advice from a fellow Japanese/Mandarin student who dipped into Korean:
1 - Hangul is easy. As Andreas said, nail that before anything else. I remember a friend telling me you can learn it in an afternoon but I laughed it off. Turns out she wasn’t far off. It’s dead easy and super logical.
2 - After this I learned some loanwords that read exactly as they’d sound in English. This really boosted my motivation early on. Not sure why but it’s something I love to do as it gives me the illusion I am learning stuff fast! We wrote an article with 60+ here - 63 Korean Loanwords {Konglish} | This List Will Surprise You
Funnily enough, one relevant to us…
3 - Take care of the pronunciation. The romanization is a bit confusing because many Korean consonants come with two potential sounds. For example ㄱ is pronounced g or k and ㄷ can be d or t. It took me some time to truly understand this although I think I still never quite fully got my head around it. Take care of that and ask questions.
We wrote a blog on the alphabet here to maybe help give you a head start - https://flexiclasses.com/korean/alphabet/
Flexi Classes has 4 Hangul classes with an extra review class so I’m confident after doing those you’ll be fine.
After that I’m not in a position to add much more I’m afraid!
I took the first chapter of Flexi Classes in Korean before stopping. For me, juggling 4 languages with a full time job was unrealistic! 3 is enough 
Korean is one I will come back to in the future but I hope to hear you make some great progress, which I’ve no doubt you will.
I am sure @Marine has a few tips as an avid Korean learner as well.