Lip Buzzing - A trumpet by itself makes no sounds.
All sounds through a trumpet come from the lips at the other end. Because of this, a player must first develop the ability to control the vibrations of the lips to make sounds.
To turn a lip buzz into a real embouchure, work on sneaking the buzz into the horn. Buzz your lips, and while buzzing, gently bring the horn into playing position. This will produce a note through your horn. Continue to play until you need a breath. Then remove the horn from your lips, take a breath, buzz and sneak the horn back into position. Practice doing this for every breath until this becomes your natural playing setting.
For more detail, contact me.