Question about coming into “season”

For context my little girl will be 2 in September, and I have never had an intact female before. All of my other females have been spayed. What are the signs to keep watch out for in order to keep the male dogs away from her when she starts her cycle? When she does come into heat, I will get her some doggy diapers to help with unwanted discharge and also if a male does get into my fenced in yard where she is while going to potty. I do let her stay outside by herself during the morning, just to let her get some fresh air and exercise. I do plan on breeding her, but not right now. I need to have her umbilical hernia fixed before she gets bread to keep her safe and no risk ot her health. Any advice will be appreciated