Flea and tick, vaccines, vet exam

All 6 of these dogs have never seen a vet let alone been on a walk. They are all barely a year old maybe to for the big white and black male. I don’t want help for me I want help for them. And maybe a tad bit of help for helping me treat my home and cat of the fleas I accidentally brought home caring for these dogs. I need to treat them, their environment, my cat my home. I’m out of my depth here so I’m assuming 500 to 1000 is enough to treat everything and everyone