How do you say “hello” in Spanish? It depends; if it’s an informal greeting, such as, saying “hi” to a friend, you would say:
Hola — Hello or, Hi
Qué tal? — What's up?
However, if you want to make a good impression to a new friend’s parents — whom you have not yet met — for example, you would say:
In the morning…
Buenos días — Good morning
In the afternoon…
Buenas tardes — Good afternoon
In the evening…
Buenas noches — Good evening
Note the spelling of “good” in Spanish; día is masculine, tarde and noche are feminine. So, use the correct gender of bueno.
If you want to meet someone and need a little more to go on that just “hola,” you must be thinking “how to introduce myself in Spanish?” — an interesting “scenario” article.