when to stain new deck

We live in Charlotte, NC where summers are hot and humid with frequent rain, and winters can be below freezing with occasional snow. Our deck gets full sun most of the day. We just had a new PT deck built about 5 weeks ago. Our contractor says it is ready to stain. Some of the boards are dry to the point of cracking already, some boards still seem moist to me and have a green coating on them. I'm wondering if we should wait a bit longer? Some of the boards are warping. Will staining/sealing keep that under control? We're also concerned because we have 4 dogs who track in red clay soil on their paws. We don't want the wood to be permanently discolored from that so feel that we should stain/seal sooner rather than later. Thoughts? When we do stain, what product do you recommend for our situation? Our deck is large, so we want the process to be as easy as possible. The more I read, the more confused I get so I appreciate input