So, just to clarify the computer you installed it on. Is the computer something that’s in your posession, that you can physically touch? Or is it server space that you are buying from a hosting company?
If it’s in your posession, then it isn’t with configuration. It’s that the world can’t see your computer. You’d most likely be able to see it at http://localhost/Omeka in your browser, but no one else can.
If it’s server space from a hosting company, then they’ll be the best guide to getting a domain name to associate with site.
If it really is a computer in your posession that you want to make visible to the world, that’s possible, but a bit beyond the scope of Omeka work – it gets into networks and server configuration that’s unrelated to Omeka. In virtually all situations, you’ll be better off with one of the first two situations.