Hi and welcome. Well you seem to be getting the exposure ok, maybe a little underexposed, Pentax does tend to do that so you should check your manual and find out to compensate. I might as well suggest it because if I don't, someone else will
Get yourself a copy of 'Understanding exposure' by Bryan Peterson.
You should also read this ;
Rule of thirds - Wikipedia, the free encyclopedia it will help you with composition.
IMO the best shots you compositionally that you posted hera are the first and last two. In the first one, it would have been even better if that curb had dissected the corner.
The second to last shot (the flowers) is a nice example with an in focus foreground and a pleasant looking out of focus background.
The last shot is a nice balance of light and dark, almost a yin and yang image. I also quite like the triangle between them at the top.
The other two shots are nice but too centred.
It all starts to fall into place after a while,just enjoy it .
Good start, I look forward to seeing more from you.