My boyfriend is away on business in Cananda, he has at&t and i have verizon . I plan on talking to him and texting him while he is away . Do I have to change my plan to international??
No, but HE will need to be sure he can call and text internationally (from Canada). You will still be in the US, making and receiving calls to and from a US number (his cell) so nothing changes for you.
Since he will be "roaming" or using international towers, he'll need a plan to cover that or pay the international rates... AT&T can give him what it will cost for their network.