My furnace fan will go on when I turn it on, but the heat doesn't go on. There's no way to light a pilot light that I can tell... what is the problem and is there a way I can fix it by myself without having to call in a service person?

If you can find the control board, there should be an LED on it that will blink a 2-digit error code. Let us know what that is.

See also this post (https://www.askmehelpdesk.com/appliances/weathermaker-8000-gas-furnace-no-heat-181632.html). It could be the Hot Surface Ignitor (http://0.tqn.com/d/homerepair/1/5/w/5/-/-/hot_surf_igniter.jpg) (i.e. there is no pilot light). Watch this device while someone turns your thermostat to call for heat. You should hear a fan start, then shortly later the HSI should begin to glow. After that, the gas valve will open and ignite (when all is working, that is).

Best of luck,
WallyH

Gas furnaces have a "pressure switch" that prevents the gas valve from opening if the venting is clogged in anyway. There is a tube going from the blower housing to the pressure switch. The pressure switch is round and about the size of a silver dollar. Check to make sure that is free of obtruction. This is a common problen at the begiinning of the heating season.