The difference between “to do something” and “to have something done” lies in who performs the action.
To Do Something
Meaning: You perform the action yourself.
Example:”I will do the laundry.” (You will wash the clothes yourself.)
To Have Something Done
Meaning: Someone else performs the action for you.
Example:”I will have the laundry done.” (Someone else, such as a laundry service, will wash the clothes for you.)
More Examples
To Do Something:
“She will paint the house.” (She will do the painting herself.)
“He is fixing his car.” (He is repairing the car himself.)
To Have Something Done:
“She will have the house painted.” (Someone else will paint the house for her.)