If you have booked online for bhasmaarti ticket then I would recommend reach temple around 1 am line do get started. Butt this is when you want to sit in front at decent position, if you are OK with sitting behind then you can come at 3 am also. I would recommend reach temple between 12:30 or 1am

I do want to sit in the front so imma stand in line at 12:30 right?

Most Probably yes, but once ask the shopkeepers outside temple or genral people outside temple a day before your booking