I can't see creating folder tab on the dashboard where it is supposed to be. Is it because I'm not an administrator of the lab account?
You have to be an administrator in the folder where you want to create sub-folders. Please request your project administrator to make you a "Folder Administrator" in that folder. Here is some documentation on configuring permissions: https://www.labkey.org/Documentation/wiki-page.view?name=configuringPerms.