As long as you're not talking about Using two domains with the same wordpress install IE you use the same site with two different names.
If you are using two DIFFERENT wordpress installations, this is super simple. Its all about associating that second domain with your webhost, i suggest you look into using your second domain as an addon domain. Given that you've just got started I imagine you're in a shared hosting solution like godaddy.
Godaddy would have you add an addon domain, or you could use a subdomain and point that to a given folder on your server.
You will ofcourse need a seperate database, and to install wordpress in that folder but you should have no issues.
IF you used something like softalicious or some hosting provided installer you are a in for a little headache as at this point you need to understand how to put files on your server. That would involve ftp etc.
I hope this helps. But really your question isn't a wordpress question its a hosting question one specific to your hosting providers pattern for using multiple domains with their servers.