Hello haggis, welcome to the forum!
My single favorite walk-around lens is the DA 35mm f/2.4 AL, aka the 'Plastic Fantastic'. There's a dedicated thread here;
https://www.pentaxforums.com/forums/122-lens-clubs/196639-da35-f2-4-plastic-fantastic-club.html
And if the first two pages don't sell you on the versatility of this lens, nothing will!
35mm on the APS-C format equates to roughly 52mm on a full-frame format, the focal length that was considered a 'normal' lens back in the 35mm film days. Although some will disagree, it was believed to match the normal human field of view, ie, how we 'see' the world, our field of vision. Perhaps, looking carefully at the photos on the linked thread will reinforce this theory, or you might prefer a wider angle, or longer FL.
There are very few lenses that are good for both scenics, portraits and can also be used for close-ups, low-light work, group photos or candid 'street' work. IMO, the DA35 comes closest.
No, it's not as razor-sharp at closeups as a dedicated macro lens would be. I've always maintained that a true macro lens is an essential purchase if you're serious about macro. The 100mm (roughly) f/2.8 1:1 Macro, made by several companies, is best for insects and flowers.
The other plastic fantastic, the DA 50mm f/1.8 has softer bokeh and a nice telephoto 'look' for tighter portraits, but is a bit long (in focal length) for indoor shooting and group shots.
https://www.pentaxforums.com/forums/122-lens-clubs/233786-fantastic-fifty-da-50mm-f-1-8-a.html
The DA 35mm f/2.4 bokeh is pretty good wide-open, but gets a little jittery stopped down past about f/4.0.
Hope this helps!
Ron