The environment is an essential part of your classroom community. The physical, emotional, social, and cultural nature of the space will influence how students engage with one another and learning. How are you organizing the space to ensure universal access? How are your students able to make the space their own? How do norms, routines, and communication work together to ensure a safe space for taking academic risk?
Considerations for designing your classroom with UDL: https://udlresource.ca/2017/12/classroom-design/
We start each class, each day with a 2-5 minute "mindfulness" activity. These are great transitions that allow one to refocus and be present in the day. Be sure to put laptops at "greater than" (<) and put mobile devices down during the activities.
A good introduction to mindful activities for kids and teens: https://positivepsychologyprogram.com/mindfulness-for-children-kids-activities/
5-10 minute mindful activities (geared toward younger students- can be adapted up) https://www.teachstarter.com/us/blog/classroom-mindfulness-activities-for-children-us/