Red wigglers are "litter" dwellers, meaning they like to live in layers of leaves, newspaper, coir, or similar matter.
The rate of reproduction depends on several factors: the initial population, the mix of ages in that population, the temperatures they experience in their habitat (which needn't track directly with the ambient temp--my worm habitat is protected from swift changes by being in the carport in deep shade under a wool blanket), what they're fed, etc.
Don't overfeed them. You'll know if you're overfeeding them the day you open the habitat and a terrible odor arises + the sight of uneaten food. Bleah.
Many of us on the forum are involved in worm composting. Search the forum on terms like
Eisenia foetida *or* Eisenia fetida
and you'll find TONS of info.
How many did you order, and where will they be living?
Sunset Zone 17, USDA Zone 9