Shorter strides, quicker turnover is key to a successful run. Overstriding is one of the biggest mistakes new runners can make. A great tool to use is run with a metronome. Typically running from 160 to 180bpm will not only shorten your stride, but it will make you a better runner in the long run. Having your feet underneath your center of mass with a slight forward lean at the ankles can cut down the number of injuries you'd get from the constant pounding of overstriding. You want to put ground behind you rather than trying to reach out in front of you to get faster. It takes time and is not something you can change in one run. Give your body time to adjust to running with proper form. Trust the process and stay injury free.