Welcome to Pentax forums, where you never know which topics will blow up into a heated debate and then go rather off topic.
I am unclear on exactly which lens you have.
Just to restate, if it has and A setting just set it to A and leave it there and its 100% like any other new lens with the exception of possibly having to manually focus.
If you wanted to do all settings manually like an old film camera you set the camera to M mode and use the front and rear dials to control aperture and shutter speed. The camera will stop the lens down to whatever aperture you indicate when it takes the picture. Its not like an old film camera where you have to physically turn the dial on the lens to override the aperture setting.
You could also just leave the camera in automatic (green) mode and have it do 100% everything. Or use the various other modes to override some settings while letting the camera do others.
If the camera seems too complex just use automatic (green) mode and bring the manual with on the trip, then when its not doing what you want just look up how to override that one thing. Its totally impossible to learn to use everything at the same time, the manuals are really crappy for that.
If you are not familiar with basic photography just leave it on automatic (green) mode until you have studied up or you wont even know what to start adjusting and things will turn into a mess.
If you really wanted a camera that is always on automatic a DSLR might not be the best choice as its big and clunky and 90% features you would never use.
Also I should mention if that lens is your only lens you will definitely need a wider zoom lens to go with it like the 18-55 WR kit lens or something.
You may want to back up and start by stating your previous camera experience level and what you intend to do with a camera in the long run if you want suggestions on what is right for you.