Noob question: How do i remove those default pre written blog posts, without removing all my posts? i just cant figure it out

Where are these pre-written posts coming from? The only one that gets added to a fresh install is the “Hello World” post. So it must be a plugin that added these (or some other person before you).

Regardless, you just go to “Posts” within WP-Admin and then delete whichever post you want to delete.