New 1976 Owner with Limited Skills

Group - I just bought my first Corvette -1976. I have no experience
with working on cars at all, but am a fast learner. I drove it home
last night and found out that the heat doesn't work. I'm not sure
where to begin to search for the problem. Is this something that I
can fix myself or should I take it to a mechanic?

For diagnostic purposes - the fan blower works and both dials on the
control panel move and air flows both at the top and bottom. I put it
on defrost, heater, and vent and had the same frigid results.

Any help will be appreciated...