I am very much into Native American Artifacts and would like to know what steps must be taken to be a legit artifact authenticator.
the only way to determine if an artifact is genuine or fake is become a curator of a museum which involves obtaining a phd in either anthropology or art history. it should be understood that many of the great museums in the world still hold fakes within their collection and often it is quite difficult to spot the not.
There is no such thing as a "legit artifact authenticator," by authenticating artifacts you are perpetuating the idea that it is okay to loot and thereby destroy archaeological sites to find artifacts given superficial value by a grey market. Once an artifact is removed from it's primary context it will lose most of it's value to science. Plus you are being quite insensitive to the Native Americans whose ancestors made those artifacts. While archaeologists do dig and find things these artifacts would otherwise be destroyed by the roadway or pipeline that the archaeologist is digging in front of. Finally your authentication could support the illegal sale of artifacts and that could wind you up in hot water from the law.
If you really want to pay homage and do something creative I'd recommend you make your own projectile points, or other objects by imitating the style of the Native Americans you like. There are many books written on the subject of projectile point creation and the craftsmanship behind the bow and arrow shafts, and fewer, but still enough to let a lay person begin to learn how, to make other objects used by Native Americans.
Finally, unless you can be sure of the context (you dug it up) there is no way to say if an artifact is actually authentic. Therefore any arrowhead presented to you as real could have been made by a skilled replicator.
good luck gingerita