I don't understand cat behaviors

I am not what most would call a cat person. We have always had cats, and I will take care of them and play with them a little, but I am more of a dog person.

Hubby, however, was all about cats. He loved them to pieces. When we downsized to a little studio apartment our kids got us a kitten for company. She immediately adopted him and treated me like the "spare". That's OK, I didn't mind. She earns her keep by being a great mouser. She has been with us for 6 years.

We lost my husband a few months ago after a long illness. The cat, Slinky, was so comforting to him. She slept with him, played with him, sat on his shoulders, etc. They really loved each other.

And she very obviously mourned him when he passed.

Now I have been adopted. She is a comfort to me. But again, I don't know cats well enough to know how to read her behaviors and know what she wants.

She will yowl at me to follow her to her food bowl, but it will be full. She will sit down and eat and I will walk back to my chair. Then she is fine.

She kneads her claws into my skin. It hurts but I don't think she is trying to hurt me. I just don't know what she wants.

I guess my questions just boil down to how do you know what a cat needs?