Greetings Kathleen:
Eastern redcedar (Juniperus virginiana) is dioecious, meaning this specific conifer has male and female cones. Therefore, cross pollination would be required (i.e., a male tree and a female tree).
However, there is some evidence to suggest that eastern redcedar may also exhibit male and female cones on the same plant.
My suggestion to you would be to contact some local nurseries and ask them about their nursery stock. No advance or special care is needed for eastern redcedar as this particular species is pretty hardy and pops up commonly across a wide range of environments.