Once you know what breed of dog suits your lifestyle and what health concerns are prevalent in the breed my tip is to either rescue from a shelter or go to a reputable breeder who does all the breed club suggested clearances, proves the dogs in some way and offers a good health guarantee. Please, no pet stores or BYB.
Have you had a dog before? If not, it's going to be a bit like learning a new language. But such fun, welcome.