I might look for some perforated sneakers instead because I'm not a fan of any of these. For walking I wand a comfy supportive shoe, so a sneaker, but make it fashionable, and in summer heat, perforations.

I know you said not sporty, so maybe perforated Oxfords.

I would go for 1, but I am not a fan of closed toe's. Iwear flats , bit the rest are all peeptoe's.

It's very personal, and it depends on how it looks once on the foot. Results might be surprising.
Take comfort in consideration, as well as your overall style. 4 looks like it would be the most comfortable.

1 and 2 seem to be leaning towards an urban chic look, whereas 3 and 4, a more boho style.

Myself I would first be attracted to pic 1.

I'm the outlier this time. I'd wear 2 and 3. The others look too heavy and hot for my summer. Though I do like the pointy toe leopard print pair very much, too.

Where can we buy these shoes?

I like the look of #1 best, and hope it's comfy.

I have Clark sandals similar to pic 2. They don't get any love here, heh. Admittedly they don't photograph well. They're not fashionable but I've worn them for practical reasons. I'd love to find a pair of navy shoes similar to Aida's finds.