The key will be to have two email addresses. One associated with you as a parent, and another associated with you as a teacher.
You will be entered into ClassroomParent twice, once as a parent and once as a teacher.
Typically, the teacher will use their school email address, and the parent will use a personal email address.
The benefit of doing this is both so the teacher can perform actions in their capacity as a teacher, and also so that when their student(s) graduate out of the school, they will still have access to CP as a teacher.