do i have to answer a message if i dont feel comfortable even going to the meet and greet?

You should ALWAYS respond to a message from a client or potential client and let them know you don't feel it is a good fit for you, this is just common courtesy

Yes should answer and politely tell them it’s a bad fit. I’ve had to turn down 3 clients now because their dogs were unaltered and even though I have it listed in my profile that I don’t accept unaltered dogs in my home they still contacted me.