Mormons can date whoever they want. They have their free agency to choose. 
 
Members are counseled to date other members who share their same values and to marry in the temple, but it's up to the person who they want to date. It is not a sin to date others of other (or no) faiths. But as they say - you marry who you date. So as a result Mormons are encouraged and advised to date other Mormons.

The only rules for dating is obey the law of Chasity (no premarital sex).  
 
Dating for Mormons is strictly platonic and the sole intention is to find an eternal parter. So many tend to shy away from non Mormons dating relationships but there plenty of Mormons that date and even marry non Mormons.  
 
The biggest thing to understand though is that Mormons tend to be very devout and openly speak of God and Jesus Christ. If him discussing God or Jesus Christ with you could offend you or upset you then you should be forwarned that it the subject will be discussed most like.  
 
They will also mention the Restoration and our Church. Since dating is seen soley to result in an eternal marriage performed in a holy temple.  
 
These are things to consider and discuss with the guy you like.  
 
Thank You for the question!