description of the scene outside of school at hometime?Watch
So for example I imagine the school, the building, doors and gates. Then there is likely lots of students walking between these. So that's for sight. Have a think and imagine what you can hear, smell, taste and touch then write it down. If it helps then add in another step, go from imagine to write down rough notes or ideas then do it into sentances. That's what I do even for posts like here because I can't think of ideas and make a sentance that makes sence, has good spelling etc before I forget the ideas.