Im learning too and I have a similar situation! It might be easier, since youre busy, to do what I do and just read a phrase a day and incorporate it into your conversations or even just alone. Its an easy way to get basic phrases down! For sentence structure and learning that will last longer, I would recommend going to the library and checking out some language audio+books if they have them! Im currently using Living Language Korean Essentials and Complete Korean. I dont have a lot od time either but they are pretty helpful. However the pronunciation is a little unclear at times so then I would recommend listening to Youtube videos about it! Korean101 is a channel that could help greatly. thats how i got started but i still need to learn a lot haha. I hope this helps!