TYou should find Amplitube (along with other FX) under your inserts at the top of each channel strip. Just right-click on the little blue box below where it says "Trim." Amplitube can be found there. It should be listed in the box, double click on it to bring up the main window. Press F1 to bring up the Help menu. You must have audio highlighted in the Edit view in order to access effects from the Process menu.