I think the basics have been covered so I'll add a few thoughts about breeding. If you want a certain color, just get a group of that. Down the road you may want to get more of this same type and color to add some genetic diversity, but adding new colors can really cause headaches. While red and blue make purple when mixing paints, it can equal clear or brown when mixing those colors of Neocaridina. If keeping neos, there are tigers, tangerine tigers and such that can do well in their parameters that won't interbreed with them. If you grow up any shrimp that are just absolutely not what you want to see in your tank, get them out. The wild types seem to breed more true than the selectively bred colors and you can have a tank full of undesirable ones in time. But if you set up a cull tank or two, they do occasionally throw something really neat! I stare at my culls tanks probably more than my "real" shrimp tanks.
Almost any fish without a sucker mouth will eat shrimp fry. A few might make it to adulthood in larger tanks that are densely planted but if your goal is to produce shrimp, it's really best to go fishless. And fish that do have a sucker mouth largely feed on the same things they do, so even they are of limited use in a shrimp tank. I do understand that most people only have one or two aquariums and probably want fish in them, but I'm just saying for maximum benefit of the shrimp.
Most baby fish I've raised require constant feeding and water changes. Baby shrimp are almost the exact opposite, those are the things that can kill them. But while babies are sensitive, they survive being moved to other tanks (as well as surviving shipping) better than adult shrimp. I've seen people leave negative feedback because the shrimp they bought were small, but that's really what you want. Drip acclimation is considered the best route for moving them from one tank to another regardless of age.
Those baby foods like Bacter EA and Om Nom are great, but a little it goes a long way. Think about what a tiny morsel of food 25 adult shrimp get fed, then consider 25 babies that are less than 1% of an adult's mass. It's such a tiny, tiny amount that you almost feel like you aren't giving them anything. But the size of the stomach on something the size of a speck must be near-microscopic.
Nothing good happens fast in an ecosystem.