I'worried as my sister got breast cancer. Is there a bad risk of breast cancer for me just because she got it?

Know your risk. You could be at higher risk for developing breast cancer but there are many questions that need to be answered: how old is your sister? Are there other family members affected? Is there ovarian cancer in your family? How old are you? Age at first period? How many pregnancies and at what age of first full term delivery? To name a few. I recommend you seek out a breast surgeon or genetic counselor.
Possibly. Your sister can have the genetic testing to evaluate the risk for the family. According to this you can get tested. Most cancers however are not genetic but related to other controllable factors such as keeping a healthy weight, being plant based, less fat, less alcohol (less than 7 per week), exercising, vitamin d levels, smoking and balancing any hormonal problems.