It's not impossible to tell the sexes apart, but it's not easy, especially when they are young and females are not berried. Males are much thinner in the body, females rounder and a bit fuller along the underline. But usually I would try to buy mostly berried females to start with, and usually at least one or two of those who were not berried would be males.
A Ghost colony take a bit of effort though, because they do have larvae rather than tiny replicas of themselves. It's best to have a separate tank to raise the babies in, because the parents do eat them if they find them once they're old enough to start grazing. Once the little ones are about a half inch long, the parents ignore them pretty much.
The female shrimp drop their eggs when it's time and they float to the surface and hatch. I never could see the larvae, but I've heard some say they can see them. In about 4-5 days, depending on temps mostly, they morph into shrimplets, which will hang upside down, motionless, just below the water surface for a few days.
During this time they don't swim, and only eat what gets close enough for them to grab. I fed mine microworms during this time. At night they sink to the bottom, and when the lights come on in the morning, they rise up to the surface again. If the surface is quiet, it's easy to see them. If the surface is moving a lot, it's a lot harder to see them.
Once I saw that females had dropped their eggs, I took the females out. And then I fed the tank some cultured greenwater. I grow a few different species of single cell algaes, to feed my fan shrimp and clams, and it's ideal to feed shrimp larvae. The larvae can only eat foods of less than 5 microns in size.. a reasonably mature tank should have enough infusoria of the right sizes to feed larvae, but my first brood tank was set up overnight and I didn't think it would have anything much for larvae to consume. It worked, in any case. I put about 75 mls of greenwater into the tank twice a day.. 5 G tank.
The tiny shrimp moult often, so you'll see wee shells floating around. After their first few days, they begin to swim and very soon after that, they're behaving just like adults, grazing on any available surface. I didn't have to feed them at this stage, they found all they needed on the sponge filter, wood, rocks and plants. Started feeding a bit when they were getting close to half inch size.
Best temp for larvae is around 72 - 74, and kept steady. Sponge filter saves them being sucked up, and I did water changes by sticking an air hose into the uplift tube of the sponge filter, so as not to risk sucking them up either. I had a black substrate, so they were easy to see once they were walking around on the bottom and the plants. I had a lot of plants in their tank also.
They will breed and berry pretty reliably.. and I even had a few that survived to adulthood in my 29G community tank, but not a great many. But there were plenty of fish in that tank, so I was pretty amazed that any larvae survived in that one.
As they get older, you'll notice their shells get darker, sort of an orange colour, and assorted dark streaks and marks show up. You may also notice that some of them have bright orange 'dash' marks, one on each tail segment, plus a 'wristband' around the front pair of legs. Not all of them sport the orange dash marks, but many of them do.