Thank you for adopting a rescue dog or rescue puppy. If possible enroll in Pawsitive 1st Step Foundation Class. Your group class, book and individual consult will get you started with training and establishing trust and communication.
Here are links to help you:
Bringing Home a Rescue Dog and the 3-3-3 Rule Rescue Dogs 101
Bringing Home a New Dog Sampawtico Training
How to Choose a Rescue Dog Jolanta Benal, CPDT-KA, CBCC-KA
Also see my Self-Help section