I'm having problems with blog posts

Evert time i create a post it uses the same permalink it is created under the permalink of one of the pages that is in the submenu, i can’t change it like when i change the permalink from a page.
When i was using a page with the blog template i got no problems because even if the permalink leads to contact when i click in tha blog page it was showing me all the posts.
But i want to use the portfolio as a display page of the posts, so i would like to know how can i change the permalinks of the posts.

Thanks.