Different dog breeds are appearing all of the time. There are breeds such as the Dogo Argentino, Barbet, Belgian Laekenois, and lots more that were first registered or recognized in the year 2020. With the appearance of so many different breeds in a single year, it is easy to think that creating a new breed is as simple as mating two different breeds. However, it is not that simple, well, not to have them recognized as breeds. Until that point, they are seen as mongrels.
The reality is, that the creation of a new dog breed can take many years, if not decades for them to be registerable. Crossbreeding alone is not enough. You need to have a clear set of traits that are apparent over many generations. That task alone will take a lot of patience and consistency. However, although it sounds pretty easy to do, you have no idea if you will succeed in the end, nor do you know if the breed you are trying to create has already been attempted or not.