For most people, lifting weight first is a better deal. You can reverse the order if your motive is to improve your speed or you are preparing for a marathon. In such a case, you can take up cardio first, followed by a strength training session. This way you would be able to put your maximum output on the cardio session, which is your priority. For example, if your goal is to run for 5 kilometres at a certain speed, do that first because if you will run after a strength training session you might not have that much energy left to finish the task. But do not skip the strength training session. Even if you are working on your speed, weight training is essential to reduce the risk of injury and strengthen your muscles.