Take a look at some online instructions for finding proper seat height on a bike. Your leg should be nearly straight if you are sitting on the seat with your heel on the pedal at it's lowest position. Given that guidance, you should not be able to touch the ground while seated (perhaps if you have size 12 feet you might be able to get toes on ground). It's normal, you'll get used to it. My knees start having sympathy pains when I see people riding with their knees all bent. Don't ride like that on a road bike.