Crystal reds are INTENSELY difficult and are definitely not a beginner shrimp. For beginners, you should go with some type of neo. Cherries (any grade, including Fire Reds) are the hardiest and easiest to keep. The other neos are hardy, but Cherries are the hardiest - they're the "original" strain.
You should never mix any neo species or any caridina species, or you will have interbreeding - so don't mix yellows and cherries or fire reds.
You could, once you get experienced with shrimp, mix crystal reds and cherries.
At a pH of 6.0, I'd be concerned about your water not being quite hard enough for the shrimp. If you add Fluval shrimp stratum, that may bring it down even a bit lower, and (although sometimes the shrimp, especially crystals like it a little lower) if it's too low you'll have a lot of problems. I keep my cherry tank with Eco-Complete because it's planted, but any inert substrate would be good. Sand is a great choice for shrimp, because the grains are tiny and they can really juggle them around.
You should think about investing in GH and KH test kits, and even a TDS meter if you are looking at getting into expensive and tough shrimp like Crystals. I would test GH and KH anyway for the cherries, because 6.0 is a little low for them, and you want to know what your base numbers are in case you need to look at remineralizing the well water.