The nearest masjid from me will make the first Jumuah azan 5-10 minutes before the time starts and then 5 minutes later the second azan will be made, after that Imam will preach Khutbah. If I pray Jumuah in that masjid is it acceptable.
بسم الله الرحمن الرحيم
Jumuah salah was not valid if offered before the time started. It is fardh to offer it again when the time starts. The first azan is also not valid before the time. It should be repeated if called before the time. You should offer Jumuah salah in a mosque where khutbah and Jumuah salah are offered in its due time.
Allah knows Best!
Darul Uloom Deoband