One page skeleton

Finally up and running yay!

I have a question (I am currently reading https://learn.getgrav.org/) but need a push in the right direction.

I am creating a simple website, it isn't exaclty just one page, there will be 3 in total, a main page, blog and contact form.

I would like to keep the navigation that scrolls to the relevant section of the page. But i would also like to add some more pages.

However, to be able to see the new pages i have created i change this line to true "onpage_menu: false" this then breaks the scroll to relevent section feature.

What is the best way to keep the scroll feature and add new pages to the navigation? Would it be better to create a new page for each section of the page and somehow point it to e.g. website.com/#features?

Thanks in advance.

Also, i would like to know how to change the logo on Antimatter? i've found where it's stored - images\3\2\6\6\1\32661fab024ab6e245ab6fc31a7d5ca0c1bc28eb-showcase.jpeg but putting a file in there with the same name doesn't change it? There doesn't appear to be anywhere else to do it.