Kristy, that really is very little information to go on, especially since Steve is a rather common first name.
The obvious step if your mother is still alive is to ask her for more information. If she isn't or doesn't want to give answers, you could try asking uncles, aunts, cousins, high school friends of your mother, etc. Basically anyone who knew her when she was 16.
Good luck in figuring out who your father is.