>>1253458In warm weather you might as well just continue to use shorts. I own a whole fucking wardrobe of /out/-clothing and I still use an old pair of running shorts when it's hot.
As for for pants, if you don't have any made for the outdoors you're gonna apreciate a good pair of allround pants for general use. Go for synthetic materials like nylon, polyester etc. maybe with som cotton in the mix (but not more than 50%). Basically any model made for hiking will serve you better than jeans. If you live in a warm area go for something light and if you're in northern Europe something slightly thicker so you can use them in winter times. Ventilation zippers are god-tier for hiking.
I do most of my hiking in northern Europe and must admit that I have a weakness for memeräven pants in this climate, but there's a brand called "Lundhags" that make more or less the same style of pants but at a lower cost (still pricy tho)
If thats outside of your budget just go to any decent outdoor shop and try a few of their pants. You almost can't go wrong.