As a user you can only do the latter. It is up to the data supplier to accept or reject the observation. You can also change your role.
Guests are users with no possibility of saving anything to the system.
Thus, carrying out regression analysis with any existing database is possible. On this page you register yourself as a new user. Please give your email-address, so that we can contact you, if there are any problems or other things we think you should know. This name is used to identify you in the system. Give a password you want to use.