It sounds like you are a bit confused on the difference between lift and bouyancy.
A BC provides a certain amount of lift. In an ideal world if everyone were perfectly weighted, this lift should only need to be enough to lift the weight of the air in your tank and compensate for the compression of a wetsuit at depth. For example, a steel 80 cft tank holds approximately 6 lbs of air. If you are properly weighted, you should be only 6 lbs heavy at the begining of a dive and neutral at the end of the dive. Thus, *in theory*, you'd only need 6 lbs of weight. However, since a wetsuit has it's own inherent bouyancy and that changes with depth, the BC must also compensate for the bouyancy of the wetsuit itself....this is not as much of an issue with a drysuit, since the drysuit is essentially self-compensating. A typical 7mm wetsuit can be 20 lbs positively bouyant at the surface, but at 100 ft it may only be equivalent to the bouyancy of a 3mm wetsuit due to compression, thus now is only 6-8 pounds bouyant. The BC is used to adjust for this difference.
Just because you wear 24 lbs of weight doesn't mean you necessarily need 24 lbs of lift. Keep in mind that that 24 lbs is being used to counteract the inherent bouyancy of you, your suit, your BC, and other pieces of gear. Thus, in an ideal world, you would still only need enough weight to counteract suit compression and the shift in bouyancy of your tank.
Weight integration messes things up a bit. If you are putting all your weight into the BC, you have to make sure that you can still float the rig when it has been removed. Many small dive boats have you remove your gear in the water, hand it up to them, and then get on board in just your fins and exposure suit. If you only had 24 lbs of lift and 24 lbs of weight attached to the BC, you wouldn't be able to easily do that unless you handed up the weight pockets one at a time (which is a good idea also).
Ok...now that I've thoroughly confused everything....
36 lbs is a "good" amount of lift for a recreational BC in cold water (cold water means thicker insulation, which means more suit compression to compensate for). One of the most popular BP/Wing systems is the Halcyon Pioneer 36, which provides 36 lbs of lift.
As for "do you need 24 lbs," we cannot gauge that here unless you provide more information. If, as a brand new diver, you felt you were a "little" heavy...you were likely VERY heavy. We need to know what type of suit you are wearing, what type of tanks you had, and your height, weight, and build.
I am 6' tall, 150 lbs...lanky and I use about 18 lbs in a 7mm full suit with an Al80.
