Only admin users can edit your school's users.
STEP 1
Go to Setup

STEP 2
Click Users

STEP 3
Click the Pencil to Edit the Teacher

STEPS 4 & 5
Edit the User's Info, And Click "Admin" if You'd Like to Give this Teacher Admin Permissions

STEP 6
See the Type of User Update

Admin users can edit your site-wide settings, like your behavior rubric, rewards, and students.