First, add a pages gadget

How Add pages to your Blog site

First, add a pages gadget

1. Sign in to blogger.com.
2. Click on the blog you want to update.
3. On the left side of the page, click Layout.
4. In the section you want your pages to show, click Add a Gadget.
5. In the box that pops up, click the + to the right of the Pages gadget.
6. Make changes to the layout of your pages.
7. Click Save.

Add pages to your blog - Blogger Help - Google Help

https://support.google.com/blogger/answer/165955?hl=en