Nice to see you taking part in the forum.
I live here in Yambol, and have for the past 5 years (just renewed the residency so have another 10 if I want it lol)
Don't worry too much about the language too much, it is very hard, and the Bulgarians will appreciate any effort you make.
You will find it is easier to learn when you have time to immerse yourself in day to day conversations though as the courses don't really seem to teach you the 'real' Bulgarian as they all have dialects the same as we do in the UK.
I found I could be understood in Bourgas for instance, but not in the village when I first learned.
I found I understand more when I've had a couple of vinos lol.
Wishing you all the best with the next adventure