Set start.me as your homepage
Step 1: Open Options
Click the Menu icon, and select Options.
Step 2: Make start.me your startpage
Select General tab. Type https://start.me in the Home Page box. Close the dialog box and you're all set.
More information on the Firefox website:
Set start.me as your new tab page
Option 1: Download the start.me Firefox add-on to configure start.me as your new tab page.
1. Type "about:config" in your address bar
2. Search for setting "browser.newtab.url"
3. Add "https://start.me" as value