Are there 'Master Pages' in BSS

Just getting started in BSS. I want to create more pages with the same Header and Footer, only changing the content 'in the middle'. I see FILE>NEW but that just gives me a blank page. I don't want to have to recreate the Header and Footer 25 times for a 25 page website for example. Then if I decide to change one thing in the header, am I going to have to duplicate it 25 times? I appreciate your input. I know there is a learning curve to anything new and I am coming from a heavy Wix drag and drop interface and BSS does not seem to be quite as drag and drop as it is marketed.

Take a look at this tutorial

I should also point out that you need to understand bootstrap framework to truly use this tool to its full potential. Stay at it though as before long it will all click together for you ?

It truly is pretty "drag and drop", but what it isn't is Super Newbie friendly for styling what you drag and drop lol. You'll need a bit of knowledge for HTML and CSS in order to really get the full benefits of this app and as Chris already said, an understanding of Bootstrap itself will help a lot too.