No. Prepare the area first, then get the students. Classtime should not be used for prep.
What are the DOTS for?
The Dots are where the students stand/start. To have a well functioning class, students should almost always be on a dot or heading towards one.
Should have the students run to or start at a wall/fence.
No. For safety reasons, they should always start at or head to a "dot". Running to a wall is unsafe, since the students might collide with it or trip and fall into it.