Because, God created everything, and he then created an image in himself, a man (Adam), and then Adam needed a lover so he created woman (Eve).
I believe, based on how Wikipedia repeatedly refer to Thoth as a "he", that Thoth is a man. If you are confused because of Seshat, she is only the "feminine counterpart", not "another half". I hope...
he is a boy god of messanger (the son of zeus)
Hera is female