How many different tribes where there ever?

Answer 1

That question is impossible to answer, since "ever" includes prehistory, before any written records were kept (which is exactly what the term prehistory means). We can never know the tribes that existed before Europeans arrived and began to make notes about the native peoples of North, Central and South America - many tribes certainly became extinct long before whites arrived in the Americas.

Just in North America, we do not know what tribe or tribes made up the Palaeo-Indian culture, or the Archaic Culture, or the Glacial Kame culture, or the Adena culture, or the Mississippian culture or the Hopewell culture - we do not know their languages or their religions or what they believed. The same applies to prehistoric Central and South America, so our knowledge is insufficient to give the answer to your question.