Hello Reece. Mozilla apparently ended support for XP. Even so, I have a website that lists Mozilla and 4 other browsers that will work with Windows XP. I hope this helps.
1. UC Browser2. Baidu Spark Browser
3. Epic Privacy browser
4. K-meleon
5. Mozilla Firefox
https://appuals.com/the-5-best-browsers-for-windows-xp/
Good luck, Reece.