
The BEST people /person to advise you going forward, is the person who bred your puppy. For me, and I'd done A LOT of research, plus looking after our then neighbours' gang, it was still a culture shock bringing our Whippet bitch home, after so many years 'with Basset'. Not the least being her need for the zoomies at certain times of the day. At which point my elderly remaining Basset headed for his chair. You should have been given a diet sheet, and hopefully a small supply of the food he was eating with his breeder. It's stressful enough moving out into the world, without switching a diet the puppy is used to. If, eventually you feel you need to switch, do it gradually over at least a week of mixing the old with the new.
Re the zoomies - be careful because early days with mine, she flew across the back area and under a garden bench - which to my horror, had a bolt sticking out below which I'd never noticed before. She had a 2 inch cut, which thankfully wasn't deep enough to need stitching but I thought she'd end up with a scar on her back. Not so, it grew out. Said bench ended up in the tip!
Make sure he's warm. Whippets feel the cold so don't let him stand around outside for long, at the moment. I bought a fleece jacket for mine when she was just a baby which she wore overnight in her crate. She now has 3 coats, an unlined mack for warm wet weather, a quilted fleece for dry winter days, and a fleece lined mack for the worst of a UK Winter. I'd not necessarily invest in too many coats while he's growing, unless you can afford it.
Whippet people, I've found, are very helpful. Good luck with your new pup - they are intelligent loving creatures.