What is the difference between 'has create' and 'have create'?

First, you'd need to add a "d" to the Word create in order to place it in the proper tense.

Has requires a singular noun/pronoun.

Joe, an eighth-grader, has created a rocket prototype. He has sent the diagrams of his rocket to the science department at the local university.

Have requires a plural noun/pronoun.

The students have worked on their essays all week. They have practiced how to change verb tense to match a singular or plural noun.

Using your example:

Sally has created her first fashion design.

The design students have created a portfolio of their creations.