Before buying shoes, take care what fits and what not. Don’t buy a shoe without first trying it on irrespective of what the box label says. Sizes in the shoe department can be deceptive. So if you do not try them out individually, it is a good idea to not buy it. You need to try out the shoe and see that you are comfortable wearing it - especially if you are in your teenage years. Plus, it also gives you the feel of the shoe and you will be able to make out whether it is the right one for you.
