try a mix
keep a few pieces that are fashionable with the kids like bomber jackets, chelsea boots, dad hats, Adidas gear (maybe a pair or Yeezys Runners), a pair of ripped jeans,
but also don't be afraid to do grown man stuff like blazers, peacoats, turtle necks, v-neck sweaters, beach shorts and henleys in the spring/summer,
and the beauty of 2019 is the you can mix and match styles, like fitted hats/dad hats with a blazer and chinos. Or designer sneakers with suits.
As a grown man in your early 30s you are in the best position because you can ride the line between what the kids are wearing and a more sophisticated look. The problem is going too far in one direction (i.e. still dressing like Fabolous/2 Chainz or dressing like Steve Harvey or VIng Rhames).
No stanning but alotta of Lebrons looks are great at mixing grown man styles along with youthful expression.