hey so heres a fun fact about the language of spanish: if a word ends in an o, it means male. (examples: gato, amigo) if a word that ends in o instead ends in an a, i means female. (examples: gata amiga)
so if you'd like to be correct in saying "Hola amigos!" say instead: "Hola amigos and amigas!" to actually adress all (or most (bc of nb and whatever)) people using spanish words.
Hola amigos y amigas, como estan? (Hello friends, how are you?)