Carbon is light, light =speed. So all things being equal you get more arrow speed for the same draw weight when comparing a wood/glass limb to a Wood/carbon limb. The added advantage of composite/carbon limbs with foam cores instead of wood cores, is again they are lighter still and they are not influenced by air temp and moisture. They can also suffer less from stacking and can be nicer to draw.
With carbon/composite limb, technology is doing the work for you, so you can draw less weight to get the same arrow speed.
As you progress with your archery it is almost inevitable you will buy some carbon limbs, but without good form no limb will make any difference to how well you shoot. To assist with good form, it's important to keep the bow weight within the limits of being comfortable. Carbon limbs will help you do this.
The price of good quiality carbon limbs are so low now, I see no advantage in buying wood/glass limbs, unless you need to keep the price down to a minimum, ideal for starter bows and for kids. But even starter bows are now turning up with carbon limbs too.
If you do buy carbon limbs, go for full on composite limbs, wood cores will not give you as much advantage and the noticable difference/advantage will be small.
Please consider faster limbs mean faster arrows. You may need to budget for new arrows too...