Do you mean your saved passwords? You can clear browsing history without affecting those. One way is with Clear Recent History (History menus or ctl+shft+del).

Hello I was wondering how I can clear my browser history without losing my passwords

Firefox uses "History" in two different senses:

(1) Broad: Lots of different kinds of private data accumulated while browsing -- including the cookies that sites set to keep you signed in (these do not contain your passwords, but have a token sites use to confirm that you already signed in)

(2) Narrow: a list of URLs you visited (AKA "Browsing & Download History")

What exactly are you looking to clear without removing your cookies?