You have about 4 options.
One is the old pressure tank/pressure switch pump control. This requires a large pressure tank and your pressure will be fluctuating between like 50 and 70 PSI all the while you are using water. The continual cycling on and off between 50 and 70 wears out the tank, switch, pump, check valve, and everything in a pump system. But this is the way it was done for a hundred years.
Your second option is to add a Cycle Stop Valve to the standard pressure switch/pressure tank pump control system. The CSV will allow the use of a much smaller tank, eliminates the cycling that destroys everything, causes water hammer, and the pressure to fluctuate between 50 and 70 over and over. The strong constant 60 PSI from the CSV will be much stronger shower pressure and causes the pump system to last many times longer than normal.
Third option is the variable speed pump like in this thread. They will deliver constant pressure and use a small tank. However, they are expensive, cause lots of trouble, and don't last very long. Much better for the people selling them than the people using them.
Fourth option is one of the many so called tankless controls. There are many different brands of these on the market. They use a flow switch to shut the pump off and pressure to turn it on. There are a multitude of problems from these type controllers, which again are much better for the people selling them than the people using them.
When using a 50/70 pressure switch, like when using a CSV to get a constant 60 PSI supply, the pump just will not come on if the city is able to keep the pressure higher than 50 PSI. The water will just go right through the pump. Only when the pressure is below 50 will the pump start and boost the pressure to 60 as is the setting of the CSV.