Step one would be to buy a domain name, this would be the address users go to to reach your site.
Step two would be to rent server space at a webhost; there are millions of them out there.
Step three would be to purchase a UBB license.
Step four would be to either hire a developer to do your web presance (uploading your ubb files and configuring things, doing any website type maintenance, do styling on your forum (all of which i do :hint hint:))
Then from here you should have a working site
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