First, it’s not adopting if you’re getting the dog from a breeder or pet store. It’s buying. Adopting means you got the dog from a shelter or rescue.
I am assuming you want a Pembroke Welsh Corgi. If so, you will want to start your search at the PWCCA website. The have information on the breed, (basic info, info about genetics, and an FAQ section). They also have information on Aquiring a Puppy, (the breed standard, breeder referral, and an article on how to buy a puppy, for starters).
If you prefer a Cardigan, you will want to visit the CWCCA website instead.
You may also want to do research with your local breed club, as well.
If you go with a breeder as opposed to rescue, you will want to make sure you are buying from someone who is a responsible breeder. The links above will have some information on what makes a breeder responsible, but if you need further information, I have other links I can share, (as I’m sure other Bees do as well).
Oh! I almost forgot! Corgis are herding dogs, and as such, tend to have quite a bit of energy, and tendency to herd things, including children, (nipping at heels, etc.). I am not sure if you intend to have children or not, but if so, be sure to research the breed throughly before comitting to a corgi. You will also need to do lots of training, and socialize, socialize, socialze, especially with children. Corgis, like most other breeds that are long-bodied with short legs, are more prone to back injury. So children shouldn’t attempt to pick up or carry a corgi, nor should your corgis be allowed to jump on and off furniture.