Hi, 'Ahora' means 'now' in standard Spanish, so in every Spanish speaking country it will be understood as that, and 'Hoy' means 'today'. I've not heard of a country where that was different, and I'm not sure whether the meaning is different in El Salvador or not. Although, I'm sure people from El Salvador would understand 'ahora' as 'now' if you were to use it when speaking to them.

Hola, soy maestra de español en México y tengo paquetes atractivos sobre la enseñanza del idioma. Agenda tu clase ya! :)

In portuguese: agora English: now