Around 5 miles.....
I play a lot of disc golf, and also manage a nature preserve with about 6 mi. of trails. I walk a lot, rain or shine.
I tend to wear what is comfortable for the season. Jeans (gasp!) in cooler weather, especially when doing trail maintenance. Cotton cargo or synthetic athletic shorts in warmer weather. Even swimming trunks! Plain old cotton T-shirts or the coolmax knock-offs from Walmart ($7). Never anything exotic. Shoes are always trail runners unless boots are required for foot protection, usually when doing trail maintenance. I used to wear sandals but gave up on them because of sticks jabbing through.
If weather looks like rain, a simple lightweight poncho in the daypack is all I bring. In the hot Texas summer, nothing....getting wet is a blessing.
So, for the distances you mention, wear whatever you feel comfortable in for a walk around your neighborhood. I do, almost always, have a hiking pole....re-tasked ski pole or trekking pole. That will save twisted ankles.
The only time my attire becomes "semi-exotic" (i'm cheap) is when going overnight, long distances, or travelling. Then I go for light weight and multi-day wearability.