Could you tell me if in the family tree, nobody have gotten breast cancer before will there be a range of people getting breast cancer?

I don't know. The reality is that all women are at risk. 1 of every 8 women will be diagnosed with breast cancer in there lifetime. Get your mammograms done.
Yes, probably. 8-9 out of 10 women who get breast cancer do not have any family history of breast cancer. The overall risk for a woman to get breast cancer in her lifetime is about 1 in 8. That is why regular self breast exams and screening mammograms are so important-- to pick up breast cancer early in women who have no obvious risks.
Yes. A common misconception is that women without family histories of breast cancer are not at risk. In reality, 85-90% of all breast cancers are not hereditary; therefore, all women are "at risk" for breast cancer, with a 1/8 lifetime risk in the us.