I would fill the tank with water, rocks, ect. and let sit for a couple weeks or more, with a filter running. They sell chemicals, to stabalize the water, but I wouldn't suggest using them, seeing as shrimp are sensitive to water conditions.
Red cherry shrimp are a drawf shrimp and seem to be easy to breed. With only shrimp in a tank, a dozen should turn into 50 in a matter of weeks.
I would go to a pet store (like PetLand) for your ghost shrimp. Most places sell feeder ghost shrimp for 100 for like $10-15. Dwarf shrimp should probably be purchased from a person online, because they run between $3-4 each at the store, while online you can get them around $1.50 each.
If you know anyone with a fish tank, steal a handful of rocks from their tank and wrap it in a piece of panthose. As long as their tank is well established and they don't have fish death, everything should be okay. Drop the "package" in the tank and let it sit. If you're in a hurry, this method gave me a shrimp safe tank in a week and a half.
Feel free to message me, if you need any help.