How do I get my story set up for a plague?

Hello, I'm a noob in the world of writing. I feel like I have a good vision for what I want to happen in my basically medieval fantasy story, but I have no idea how to kick it off. Here is what I want to happen: <br><br><br>I am a 19 year old womann living in a small village as a maid in someone else's chateau. There is a lot of disease present in this world. The kingdom is made up of 4 islands. One island is a plague island with a basically constant plague. One island is sort of a trade port island. One island is the most populated island with the most people on it, but it is also where most of the plague happens to be. Then there is the island I live on, which has less disease. There is a lot of disease on the other islands, and so the plague could start on any island, but I just haven't decided yet where it will happen first. <br><br><br>Here is what I want to happen: the plague happens to a trade ship from the plague island and the plague gets to one of the islands, likely my island. I get exposed to the plague by someone in the chateau, and become sick. I end up surviving the plague, which gives me resistance to this disease. However, soon basically every village on my island is sick, and even the villages on the other islands are getting sick as well. A lot of people die. There is basically anarchy on the islands, because so many people die. I eventually go on a little journey with a few other people to go to the plague island to get a cure, and we have some crazy stuff happen on our journey. <br><br><br>So, I am kind of at a loss for how to set this up without it seeming obvious that I want to plague to start. I want to give a sense that the plague is sort of a random event that happened. Like, its been a long time since the last time a plague happened, and so I totally want to give a sense of this world being at peace, that nothing bad is happening. But I also don't want this to come out of nowhere. So, I feel like I need to drop a few hints along the way, so that the reader isn't totally surprised when it happens. <br><br><br>I also want to set up some stuff for my island to get the plague first, because like I said, I haven't decided what island to get the plague first, so I want to set up some things for it to first happen on any of the 4 islands. <br><br><br>I basically know nothing about what it would have been like to live during the plague, and so I feel a bit at a loss for what hints to drop to give a sense of disease present in the world. So, I can use a bit of help with that. <br><br><br>How do I set this up so that the plague feels like a random event, but also not like it's coming out of nowhere?