According to Orthodox Judaism when does morning begin? Does it begin at sunrise or much earlier than that?

ב"ה Shalom For most intents and purposes, according to Halacha, the morning begins at sunrise. The time of sunrise varies from location to location and is also dependent upon the time of the year. This would always be the ideal time for fufilling mitzvot which begin with the morning such as Brit Milah or blowing of the Shofar on Rosh Hashana for example or Tefillat Shmoneh Esreh with reciting of Kriat Shma just before sunrise. Under certain circumstances, it is considered day or morning already from the time of the Halachic dawn, for which there are different opinions how this time is calculated. All the best.