In episode 3 at 31min-31.30 a song plays when they go up to their secret bar. I tried shazaming it but I get a different song entirely no matter where I start the recording from. If you know it or think you know someone who knows... tell me!! help me!! Please :D

Good question, I could not find it either. I have found it easy to find listings for the OST songs in Kdramas but have a harder time finding other songs that are included in the series. An example in Fight My Way was a song I was searching for that had a lot of the lyrics in english in the subtitles and I searched but did not find it(someone on this site provided the answer via another persons query). That song, by the way was "I can't cry" by Fin K.L..

I believe I finally found the song- a band called Goonam, song is Young People https://www.youtube.com/watch?v=6Fl1Euj3-gg