I guess my honest answer is that I don’t really have a specific “style” as such. I’ve never really given too much thought to clothes.
I’ll admit that checked shirts are a favourite item of mine (short sleeved in the summer, long sleeved in the winter), although I have also got some jumpers that I quite like for the winter and some plain t-shirts for the summer. I don’t tend to go for anything overly brash, though; a lot of my clothes are quite subtle in style. That’s usually paired with jeans of some description, or cargo trousers on occasion (mainly if I’m at a park; cargo trousers are great for the practicality).
In terms of retailers; I’m not a frequent clothes shopper, so I don’t really have any strong preference. FatFace do nice shirts, and Next does me pretty well for everything else, but I don’t really go for anything designer, personally.
Shoes-wise, I tend to go for boots, but I also have a pair of Vans (which tend to be my theme park shoes, as they apparently go better with cargo trousers), as well as a pair of sandals for the summer. I used to gravitate towards thinner boots that had a more Converse-type sole, but recently got a more traditionally boot-like pair that are slightly thicker, which I quite like.