Try search this way:
For loose/washed effect tees and chinos (lots of diff chinos) - Topman
For something semi formal but smart casual clothing (like their shirt quality and varieties) - Zara
For jacket, cheaper jeans and some street tees - Pull and Bear
For jeans I personally dun have a fix brand to purchase since I like raw selvedge but it's overpriced and lack of design but u can try CK or A|X
For sneakers choices can be vary depends on ur style - Onitsuka Tiger, Geox, Vans, Converse, Zara/pull & bear (Cheaper deal but quality vary, lots of casual smart looking sneakers)

here's some sample street wear, pretty flexible and has no restriction:

why u want to be stylish ?
whats ur objective ?
looks proffesional? attracts girls?
u have to understand what image u want =)