Question 1: Normally they have a screw-in plastic level plug, and a screw-in metal drain plug. The drain plug goes into the base. For the level plug, the early ones have it down low and you theoretically fill it to the brim then screw in the plug. The later ones have it higher up and it is a dipstick.
Question 2: Have you found the choke, and are you using it? Sounds like it's one of the old ones with a manual choke, and you aren't using it, or the choke needs to be serviced. If you post a picture of the carburetor we should be able to tell which applies.
