Hello I have a well and a Jet Pump with a pressure tank , I can't seem to get much pressure to the system , would you be able to give me some suggestions on how to increase thie pressure .

There's probably a little grey box called a switch on your system, probably very near the pressure tank. Turn off the power, remove the grey cover, and turn the large center nut clockwise two or three full turns. Turn the power back on and try that out. Continue to adjust until you get the pressure you want. Word of advice: A max of 60# is about where most folks seem to stop. Jet pumps are not known for their ability to push pressure up high.

This site has a very nice description of how its done.

How to adjust water pump pressure, pump cut-on pressure and pump cut-off pressure - private pump and well system do-it-yourself repairs