I've read that Acacia honey is the best. How should I know which one to purchase if both are being sold at the same price?
Different types of honey come from bees gathering nectar (and some incidental pollen) from different types of flowers. Acacia honey comes from acacia flowers, clover honey from clover. Wildflower honey comes from bees gathering from an unknown mix of flowers, when the supplier doesn't have control over or knowledge of what flowers contributed to the honey -- assume a variety of species local to wherever the honey comes from.
Truly "wild" honey comes from bees that are not kept in a hive, and is an unreliable source at best since you have to find a wild swarm; it's unusual to find that sold commercially.
Raw honey isn't heated or pasteurized.
Which one is "best" is really a matter of personal taste and preference. The different flowers result in different flavor profiles. (An amateur beekeeper friend of mine feeds his bees sugar water to help them live through the winter, and the "honey" resulting from that was extremely bland. The flowers are really key to get flavor.)
Tasting different varieties is the best way to see what you like!
So you have two kinds of honey. One is a varietal, one is either a blend of unknown sources, or of known sources but not able to be separated because different honeys have been stored in the same combs, making dividing the honey difficult and expensive at best.
During periods of high nectar output, the experienced beekeeper knows what kind of nectar is being collected. This is because bees are fairly predictable in this sense, and once a hive starts collecting a certain kind of nectar, it will continue to collect this same nectar until the source mostly dries up or another source of nectar becomes overwhelming available and the bees switch over to the new source.
By watching the blooms and the watching the bees themselves, we can determine when the bees are making the switch. Many of us go to our hives and start collecting supers (boxes of honey comb) of honey as fast as we can at this point to avoid having supers of honey of mixed sources.
On the other hand, nectar a from different sources also are visually different from one another so you can see a pretty distinct division between the two types because the bees will never put nectar from one source into the hive cell holding another source of honey. They assign a new empty space for new honey sources. In other words there is no graduation between them. It's a distinct line. One kind of honey on this side and another kind of honey on the side.
Now...wild flower honey is simply this and this alone. It means absolutely NOTHING else. Wildflower honey means the beekeeper doesn't know what kind of honey it is, or it's a blend of two or more honeys because the bees switched honey crops mid "box". The bees don't care about boxes, just the beekeeper. So wildflower honey means honey of unknown OR indistinct sources.
What makes honey raw, is whether it's been heat treated or not. Heat treating helps stabilize honey so it has less chance of crystallizing (also called creaming), but it also destroys some of the more delicate esters and enzymes that gives honey such a wonderful bouquet and healthfulness.