Just because the chinos have a "dressier" texture doesn't mean that they can't be worn casually, especially if they are drawstring!
Chino's, tees, and sneakers, are as classic as it gets. And when worn together you feel confident in knowing that it works. For the cooler temps, wear a long sleeve tee or even throw a button down over and go.
Cheers, it's going to be a good day and you are ready for it.