Breath well
Here are two videos to help you breathe well. The first video is about calming your nervous system through box breathing. The second video is about energizing your nervous system through power breathing.
Box breathing entails inhaling for a certain amount of seconds, holding your breath in for that same amount of seconds, exhaling for that same amount of seconds, and then holding your breath on the exhale for the same amount of seconds. You can choose to make the sides of your “box” however many seconds feels right for you. In this example we make the sides of your box 4 seconds.
Power breathing entails taking a deep inhale through your mouth to fill up your lungs and then exhaling sharply through your mouth 20 times. Then at the end of the 20th exhale you empty your lungs and hold your exhale for 10 seconds. Then you repeat that whole cycle 2 to 3 times.