Meow @CR38
#1 thing you absolutely have to understand is that cats rule. Male or female, they are all Queens.
They can be aloof and appear indifferent but that is only because they are very aware of who they are, Queens. They will only come to you if they feel that you are worthy of their presence and that is established when you make it known that you understand your place is to serve them. 
They are super easy and super fun. What I do when I meet a new cat is I bow down, literally come down and put the back of my hand out and let the cat come to me. They have to sniff you out. Then if allowed, I stroke the top of their head and just see how they respond.
Definitely some cats are shyer than others and may need some greater coaxing and reassurance. Sometimes nothing works. I sat 3 weeks with a cat I only saw 4 times and it was about two days before leaving that she finally came and sat beside me.
They can hide anywhere. Underbeds, couches, closets, bathrooms, basements, pantries…I find it best to let them be and they will come as long as they are not locked in somewhere. Trying to get a cat to come out only makes it retreat more.
Tree and roof climbers will find their way back down. Same as cats that roam outdoors, usually will come home in time to eat or when they are done prowling and hunting. They like to bring home trophies for you. You can rattle some treats or offer food to encourage them to come in.
Sometimes cats will bite or scratch in play. They will let you know for certain when they dislike something and with time you will clue in to this. In my experience they are only aggressive if they feel threatened.
Cats are finicky about their food and schedule. Kitty parents also have their own preferences and methods that work for them so follow their recommendations.
The owners know them best and are your best resource for what and when to feed them, what they enjoy for play, their preferences and habits as well as their dislikes, must nots or any special needs they require.
A real good conversation and a good detailed welcome guide is your best bet.
Be patient with yourself.
Ask lots of questions and be honest about your experience.
Don’t take a sit with an animal that has special needs that you are not ready for. It is a disservice to the family and the animal.
Enjoy yourself and soon you will have lots of tips and ideas to share with someone else.