You can replicate a lot of the data and apps as others have explained. But once you get to SIM cards it’s a different game. The advice would change if you’re d

You can replicate a lot of the data and apps as others have explained. But once you get to SIM cards it’s a different game. The advice would change if you’re domestic (staying in the same country as your service provider) or international. If you’re domestic then eSIM is the way to go here, you can have a new one issued and activated fairly quickly. If you’re international you can either move to a VOIP provider or use some service (like a Matrix bridge) to share SMS messages across. VOIP would be your only real option for calls as well - both phones would just be SIP trunks and can be hot swapped or used simultaneously.