How Many Different extraterrestrials are from the Sirius and Pleides star clusters and how many have visited the Earth?

I hear about ET Humans from Sirius and Pleides coming to Earth both in the distant past to help with the new Humans here,  and also those who now are part of the Galatic Federation. 

But with all the different stars and planet orbiting those stars, I wonder how many  different species have been visiting here and helping Earth Humans?