I'll arrive at Beijing Capital International Airport coming from Europe at Terminal 2

My connecting domestic flight is at terminal 3. My questions are:
- Where is the place to enter the airport terminal shuttle (Is it a bus?) at Terminal 2?
- where at Terminal 3 does the airport terminal shuttle arrive?
- Do I have to access then quarantine + immigration service in Terminal 2 or in terminal 3?
- Baggage claim + customs service is then in Terminal 2 or Terminal 3 (because of my connecting domestic flight)?
Thank you
Martin