Again, you'll need to specify what kind of showing you're interesting in doing.
Do you just want to have some fun at the local fair, assuming it's not a terribly serious affair? These days, fairs have pretty relaxed rules and are more for the enjoyment of the kiddies than actual, serious competition. These birds could be entered in such a fair, who knows, you might get a ribbon. A lot of small local/county fairs are like this (though not all of them, I'm sure). Again, this is not what one would call a real, proper poultry show - in these instances birds are generally not judged by any kind of genuine APA/ABA Standard.
If you are more serious about the venture and want to actually compete in a REAL poultry show, none of these four birds can be shown. Easter Eggers are not a true breed but a mutt, even by hatchery standards. The Buff Orpingtons are typical hatchery quality specimens, meaning they make great pets and layers but any judge would disqualify them as soon as look at them.
If you truly want to compete, you'll need to purchase a bird from a breeder who works with Standardbred fowl. That is, they select and breed stock that conforms to the American Poultry Association's Standard of Perfection. Determine what breed you would like, and what is available in your area. Many serious breeders will only sell juveniles and adults; a few might offer chicks or hatching eggs, but keep in mind, even excellent quality parents can and will produce chicks who are simply average, and even subpar. If you get a juvenile or adult bird, you know what you are getting. And keep in mind, no bird is perfect - a show quality specimen is a bird with no major flaws and as few minor deviances from the Standard as possible.
As it would so happen, just this week an article was featured on BYC's front page regarding getting into poultry showing. It's a good article that should answer some of your basic questions:
https://www.backyardchickens.com/a/...-sport-and-not-feel-ridiculous-when-you-start
