New users are allowed to edit existing articles and pages. Through your edits and contributions you can receive the permission to create new articles and upload pictures
Be creative and be bold, you don't need to ask for permission to edit, if we make mistakes we can always be corrected, anyways. Whenever you can point to sources for your claims as to help readers analyze critically the information presented, you should do it. Pointing to sources are still optional, but highly suggested
Happy contributing and welcome, comrade!