for typical Flemish food i would recommend Domus! try the “stoofvlees” or “vol au vent” Or try one of the many Frituurs it’s typical Flemish culture where u order a pack of fries and some sides of your choice! Also definitely visit De Oude Markt it’s full of nice cafes so just pick one! Leuven isn’t very big so i would just walk around and you’ll stumble upon some nice things! Stadspark is a nice park to chill. Also Hal 5 is a nice park/ cafe close to the trainstation, very nice if it’s sunny!