For Aguinaldo9.  Once you have gained some altitude, I usually fly manually to 1,000 feet AGL before engaging the autopilot which is done by pressing the CMD button with the mouse.  Normal practice is the center CMD but you can use any one of the three.  You will need to press the Heading Select with a right click into the center and also if you have A/T engaged, press SPD.  Else, use LNAV and the FMC will take over navigating your course.  ATC will give you course changes until they turn you over to your own navigation which you can do in A/P mode easily before activating LNAV.  Now somebody solve my APP problem, please.