Did you know that you can set your start page to any built-in or custom page? Every time you log in or open a new window, it will default to that page. Here's how to do it!
In personalized navigation, expand the sidebar, click the ellipses next to Pages, then mouse over the page you want to set as your start page to show the gear icon to the right. Clicking on the gear icon will give you the "Set as Start Page" option.
In classic navigation, click the pencil icon in the tab with the page that you want to make your start page.
Then click the gear icon to the left of the page and select "Set as Start Page":