Settling in..
Installation and Configuration
From your site's ACP goto the Marketplace and add modules and skins from there.
If yours is a Ning3 site you can only import basic member info and none of their content. Do that via the tool in the NingImport module. Do it now so that you have some members to work with when developing your site. You can always do it again later to top up the site with any new members.
Checkout all our 'stock' skins to see which is the nearest to what you want then use that as a starting point for development.
Most important - Read the docs and search this forum. Most answers to your questions will be there:-)