Some time ago I inherited an accordion that is probably older than my grandparents.

Since then, I've come to really love classical music and I really want to be able to replicate it myself.

The problem is I've never played an accordion nor any musical instrument. So I am going around Google to learn about accordions.

I think I understand most things now BUT I am so confused by the bass system.

The instrument is an 120/41 piano accordion with one bass switch and two treble switches. Brand is "Pollina".

I however don't know what kind of bass system it has only that there are 120 bass buttons, the middle C has an indent on the 2nd row from the bellows, when you press one bass button a couple more go down at the same time.

I have heard that there are two bass sysyems — free bass and stradella, and that they are very different from each other.

As I am an absolute beginner at this, I need this information to be able to start learning.