Most common cause of the symptom
You are an External User on the Project. Only Project Admins and Internal Project Users have the ability to update List details. If you have not been made Admin on a Project which you are a part of then you will not see the ability to update the details, instead, you will be presented with the project details in 'Read only' mode.
Our permissions system only allows Internal Project Users & Project Admins to update the details as you can add many people to a Project and not everyone should have the ability to edit those details.
Insite Teams Projects can have three types of users; Project Admins, Internal Users, and External Users. Project Admins & Internal Users are Users who are also a part of the Plan associated with the Project. External Users are Users who have been added to a Project but are not a part of the associated Plan's Organisation List.
External Users have fewer permissions on a Project as these Users are likely not a part of the organisation who owns the Plan. For example, these may be sub-contractors to the organisation or their client or consultants. These External Users can be invited to a Project so that they can view and add to certain Lists (Open Lists) but are blocked from viewing other Lists (Internal Lists) or updating List details.
1. If you are supposed to be a part of the Organisation List for the Plan which the Project is associated with then please contact your Plan Admin and ask them to add you as a Plan user. Once you are a part of the Plan you should be able to start adding Lists to the Project.
Note: Only the User who created the List is able to change the List privacy settings. Other Internal Users will only be able to update the List Details.