1-ok, well First you are going to want to pull out the reference for your second joystick
2-Second you need to pull down a Get.vi
3-Third you need to get two unbundle by name functions from the Cluster,Class and Varient section
4-Wire the unbundles to the button and axis output
5-you need to create open.vi's for three motors (each one set to its pwm)
6-To make the motors move on a button you are going to need a case structure for each motor with the set speed.vi in the case structure set to the speed you want to move it
6-for the axis just wire axis one into a set speed.vi
If you are needing to learn the basics i suggest you watch the videos from here
http://www.frcmastery.com/