Mandolin progress? Maybe?

I have been trying some new songs lately. On the guitar I am learning "Voljela me nije Nijedna." I can play the song well enough on the guitar, but the words are in Serbo-Croatian, and the delivery is unusual. I am getting closer to being able to sing it,(2 of 3 verses learned) but I think I will need a cheat sheet for the words.
On the mandolin, I am learning my first polka - "Britches full of Stitches."
I think it's an Irish Polka, and I have heard the song in the Irish Pubs and at the Renaissance Festival for years.
There's a handy YouTube channel called MandoLessons which has been helping me find new songs.
I play often, but I can't always tell if I am improving:(
I learned this song in one day, so maybe that means I am getting better?

It's still slow and sometimes my brain freezes, but if I keep it up I think I will be able to play this song with a group.
Time will tell...