A very rewarding journey! Start with Anna Ohoiko. She has hands down the best FREE Ukrainian teaching podcasts in the universe. Everything else pales into insignificance.
She has me speaking after just 3 weeks of studying (following 6 weeks of less prolific self-study) and might make me fairly fluent by the end of this year. I spend so much time listening to her podcasts first thing in the morning and last thing at night that I have been dreaming in Ukrainian lately. In my last dream I kept repeating “Голосове повідомлення” (voice message), not knowing what it was and when I woke up I did know what it is!
There is a wealth of written and other bonus materials you can buy bit by bit as you progress. 5 minute Ukrainian and Ukrainian Lessons podcast by Anna Ohoiko.