Making sure puppy doesn’t get sick from older dog

I'm bringing home a puppy tomorrow to a house with a 9 and a half year old border collie x kelpie who lives a healthy life but is in need of a friend. What did people find helpful when minimising risk of puppy catching something from an older dog? As you can probably imagine a border collie x kelpie dog needs her walk and I want to limit high traffic areas for my dog but this is very much in her routine and they say it's important for the older dogs routine to not change to ensure a smoother transition. I have procedures in place like wiping her paws down and feeding them separately and keeping them separately mostly. I'm interested to know what other owners found helpful