Both what? do you mean your home page and the settings page?

Type about:preferences#general<enter> in the address bar.

There are two settings;

• When Firefox Starts

When the browser is started, what do you want to display. Many of us choose Show My Home Page.

• Home Page

When a new page is opened, what do you want displayed.

1. Use Current Page. Use what ever page(s) are open at that time.
2. Use Bookmark
3. Restore To Default. about:home shows a Mozilla home page with tools.

You can use any of these that you wish;

about:home (Firefox default home page), about:newtab (shows the sites most visited), about:blank (a blank page),

or you can enter any web page or about: page you want.

Note that this can happen if you click "Use Current Page(s)" to set the home page. You can pin the tab with the about:preferences page to prevent including about:preferences to the home page setting if you want to use this button (pinned tabs aren't included in the home page). To set a single page as the home page you can drag the globe/padlock to the toolbar Home button.