You should ask your LOR all your questions, but I will just point out a couple of things regarding selling chometz. These may have already been mentioned (I didn’t read this thread that carefully), and if so, I apologize.
You don’t have to have chometz to sell. In fact some people say it’s better to get rid of all your chometz before-hand and NOT to sell it. Some people will even throw all their chometz out or burn it rather than sell it (because they hold it’s better NOT to sell chometz). Others will give it away to people who do sell chometz. There is nothing wrong (to the best of knowledge) with not having chometz to sell.
However, I think you might have to do a “mechiras chometz” (selling chometz) anyhow, even if you don’t have any real chometz to sell, just in case you do have chometz around.
You should check with your LOR about that, and also ask him when you can come to him to sell your chometz. Most Rabbis have set times before Pesach when they are available for selling chometz, but it’s basically men who come, so as a single girl, you have to find out when it would be a good time for you to come. (I have a lot of experience with that. In one place where I used to live, they let me come the same time as everyone else and they let me go ahead of everyone else – that was cool)
Before you sell your chametz, if possible, you should know what cabinets,etc, will have things in them that you are selling, and you should know what specific items you are selling (the Rabbi will ask you to list the places, and he might ask you what items you are selling).
Aside from food, there are many products that may be chometz. There are also different opinions regarding which products have to be kosher l’pesach. By products, I am referring to things such as shampoo, conditioner, make-up, other hair products, toothpaste, deodorant, etc.
There are books available that list the kosher l’Pesach products. But you should also ask your LOR about this since there are opinions that some of these items don’t have to be kosher l’Pesach.