How long should I wait after cancer to have a baby?

Ask your doc. Your question is too broad as the answer will depend on site, type, grade, stage and treatment received. It is best to ask your cancer doctor.
Depends. To many variable to address here. If it was a pre-cancerous condition, such as cervical dysplasia, the wait is just a few months. You will need to talk with your OB and perhaps a maternal fetal medicine specialist to decide if getting pregnant is even advisable. Good luck.