Hello & welcome, Roberta. I am Dr. B, a licensed veterinarian and I would like to help today.
I am afraid that you may be confused by how this website works. We are able to offer veterinary advice to the public but we cannot vaccinate cats for people (especially as we are based all over the world, just as are the people we help). Therefore, as I am in Scotland and many of my colleagues are based in the US, it isn't possible for us to visit your cats in your home. Therefore, if you would like a vet to administer these vaccines, you can find your local vets via the RCVS Register (HERE). And this would be the best means of finding a vet near you to either vaccinate your cats in their clinic or as a home visit.
Otherwise, I do just want to mention that feline coronavirus or FCoV (the virus that causes FIP) is endemic in the cat population. This means that it is quite possible that some or all of your cats could already be carriers. The way to know whether they are or not would be via blood sampling them for an FCoV titre. And if you are thinking of vaccinating (especially as some of the vaccines can actually make cats more sensitive to the virus for a few months after vaccination), this would be prudent to check. And if you did find that all your cats were carriers as well, then you may be less concerned about vaccinating for this and less worried about the carrier status risk for this new wee kitty.
Please take care,