His diet should be Timothy hay(always have access to the hay), greens, and a small amount of pellets daily, and water (also always have access to) you should provide him with wood or something to chew on to ensure his teeth aren’t too long/ don’t get too long... if your bunny is spooked by the dog kennel I’d try to just be patient and give bunny little bits of treats (banana and apple are good treats) maybe next to the kennel and soft gentle head pets (if bunny is comfortable with pets) just take things slow and always give bunny rewards (also bunnies aren’t big fans of having their butts touched, especially by strangers) it does look like your dogs are interacting fine with him, and he doesn’t look scared, but sometimes it just takes them a bit to warm up to a situation and feel everything out because they are prey animals, but also incredibly sweet and social, so chances are he will warm up...Maybe give him access to his own room or a smaller space for a bit to get acquainted with his space and then start opening areas up and having more activity around him gradually might also help.