hello!
why are there so many coins to choose from, do they really each have something unique about them?
Not all altcoins are unique. Most of them are just shit coins or scam. There are some that are good quality altcoins. They really have something unique compare to the others and their developers are trustworthy and has good background. You should do your own research first before you invest on them. Beware of the coins wherein they have some pump and dump group.