Decide What To Call It
We're presuming that yours is not a top-level site, but is in fact a child to some parent site already in existence. You'll need to give this child a name, specifically a display name (or title), keeping in mind that if you call it, say, Fred, the whole name (that is, the URL) will look something like this:
There are only a couple of points to keep in mind:
- Make the name short, descriptive, and easy to remember.
- Don't use spaces.
I'm not just being whimsical here. You want to keep those titles short because you only have 260 characters for a whole SharePoint web site address.
As for spaces, any that you include will be a royal pain in the URL. SharePoint does that bizarre substitution alchemy whereby each space is magically transformed to the characters %20. Not only does this habit chew up three of those precious allotted characters instead of one, but it also makes the web address harder to read and use. Besides that, it looks terrible.
You might also need to check in-house naming conventions to be sure yours conform to any that are peculiar to your workplace or team site.