To determine how many sprinklers, sprays or drippers you may use on your system, you will need to find out the water pressure on your home system. It's important to know your pressure and flow, as you'll need to work within the water that's available from the tap (or water source). If you have a watering set up which needs more water than you have available, then you'll see reduced performance (or no performance - such as pop ups dribbling or not popping up).
This can be worked out with a flow test, using either a pressure gauge test kit or a simple Bucket Test. The Bucket Test can be measured by timing in seconds how long it takes to fill a 9-litre household bucket. More info on the Bucket Test can be found here.