I like to make small talk with clients first to get to know them a bit and warmed up to me. Usually when I’m posing them I like to demonstrate what to do first so they’re less awkward. ALWAYS be there to hype them up too saying things like “perfect, this is going to look great” etc.
I carry a speaker with me so I can play music or they can play their favorite song to jam to while shooting so there’s no awkward silences.
It might also help if your subject has a support person with like a friend or family member to make them more comfortable. Then I can always ask them “what’s something that always makes this person laugh?” to get genuine laughter.
For babies and little kids I just make goofy faces or weird noises so they laugh.
This might be a weird method but it could help if you had someone take pictures of you so that you know how they feel and can find what makes you more comfortable could also work for them.
I think any of the canon rebel cameras are very user friendly. They have a great selection of preset settings if you’re not ready to use manual + easy manual settings. I’ve have the Rebel SL2, SL3 and T7 and I’ve liked them all. I prefer my SL3 though.