The URL to the top right is the URL you need to give to Google Earth. Pressing the launch button should cause Google Earth to start running. If it doesn't, the next best way is to drag your mouse over the URL until the whole URL is selected, then drag and drop the URL into a web browser. After that Google Earth will be started and everything should work.

Click Always on top if you always want the planOfile program to be running on top of every other window. This is useful if you only have one monitor and you need it to be above Google Earth while you're adding trip points or waypoints.

Select the units you want to work in. Everything will be displayed in those units.