You first install the drive side fixed cup and get it TIGHT. Recommendations for the installation torque vary from 360 to 600 inch-pounds which a lot. If it's an English or Swiss threaded bottom bracket (left hand threaded for the drive side cup), tight is important. If it's French or Italian (right hand threaded drive side cup) tight is essential. You should apply a heavy bead of grease around the ball race inside the cup and place the balls in it first using the grease to keep them in place. You can install the balls after the fixed cup is in place but it's a lot more awkward as you have to to reach through the bb shell. I use long tweezers if i have to do it that way.

Then insert spindle, adding a layer of grease to it's races first followed by threading in the adjustable cup with it's bearing balls also bedded in a heavy bead of grease. Finally, tighten the adjustable cup until the play in the spindle just disappears and then thread on the lock ring and tighten it while holding the adjustable cup from turning. You may need to make the final play adjustment a few times to get it right. There should be no play but no binding.

As to the amount of grease, I use a lot. I bed the balls in a heavy bead and then add another bead of grease to completely cover them before installing the cups and spindle. It may be overkill but does no harm and gives the best protection from dirt and water. A plastic sleeve can be added to the inside of the bb shell before the adjustable cup is installed as extra protection. Your bike shop probably has these if your bottom bracket didn't include one.