How can I help a studio if I am it's curator other than adding projects to it..???

Well, if you're a curator then adding projects (and removing projects you added) is all extra that you can do. However, if you're a manager you can add and remove curators. You can promote people to manager, change the image and edit the title and description. Of course, as a curator there might be things which would make sense for you to do rather than a non-curator, for example, you could answer any questions about the studio in the comments section.