In order to log into your site it will require your UCM net ID and password. If after following these steps you are still unable to edit your site either contact an acting site manager to assign you permissions, or if one has yet to be assigned contact firstname.lastname@example.org.
1) Navigate to your site's url depending on whether or not your site is live or in development the url may be slightly different but it does not matter as the process is the same for both
2) Login by using /user
3) Input your UCM Net ID and password