I think you will find a lot of answers to your questions if you choose to purchase the ebook I referenced below
you may want to spend time reviewing this - I found this by googling how to use the Pentax K 1
how to use the Pentax K 1 - Bing video
or other free resources
line 1 of the following chart indicates the capability of the K 1 and what exposure modes ( here explained ) will work with various Pentax lenses
" Exposure Modes-
M Manual exposure, you set shutter speed and aperture. Camera's exposure meter will indicate when the setting is correct.
M' Crippled manual exposure, you set shutter speed, lens will always stop down to its smallest aperture during exposure. Camera's exposure meter will indicate when the setting is correct.
M" Manual exposure without light meter.
M''' Manual exposure with stop down metering. You set the aperture on the lens, press the green button/AE-L button which stops down the lens and sets the shutter speed as per the metered value.
Av Automatic exposure, you set the aperture, the camera sets the shutter speed
Av' Automatic exposure, the camera sets the shutter speed, the lens is always at its smallest aperture.
Av" Automatic exposure, the camera sets the shutter speed, the lens is always at its widest aperture.
Sv Automatic exposure, you set the ISO, the camera sets the shutter and aperture, only on the K10D
TAv Automatic Exposure, you set the shutter speed and aperture while the camera automatically sets ISO, only on the K10D
Tv Automatic exposure, you set the shutter speed, the camera sets the aperture
Tv" Correct exposure may not be obtained, since the lens is always set at its widest aperture.
P Automatic exposure, the camera sets shutter speed and aperture. On some bodies more than one program line or a number of "Picture Modes" can be selected.
http://www.mosphotos.com/PentaxLensCompatibility.html
I have found this chart helpful as well:
http://www.mosphotos.com/PentaxLensesExplained.html