I see there is more confusion than I thought at the beginning, so I will probably make a better tutorial function. There is the journal(also in the options), but it seems still too confusing.
So to answer your questions: Mountain tiles at the beginning are the top, left and right borders of the map, so you should build stone mason there.
And for leveling up, you have to first invest some science after building a school. In most cases the first science levels reaveal something new.
Hallo guys, this is the first game I'm publishing and it's in a state where I find it ready to publish. Still if you guys have ideas to improve or find any bugs please tell me. Also english is not my mother language, so please don't be rude if there are any such mistakes.
But I would be happy if someone would leave any constructive feadback here.