I'm' is a contraction of the words 'I am.' By adding a verb to 'I'm' this lets you express an action or occurrence about yourself.

Here are some examples:

"I'm eating lunch."
"I'm brushing my teeth."
"I'm scared."
"I'm driving to work."
"I'm crying."
"I'm typing an email."
"I'm cooking dinner."
"I'm combing my hair."
"I'm hanging a picture."
"I am texting."
"I am dancing."
"I am interested in the job."
"I am exercising."
"I am sad."
"I am learning."