How can I giving an approval or confirmation to the submitter?

After they fill up the form I create, they need to have a approval or answer from me. but how to do it?

You need to set up a workflow approval process in your form using the conditional logic. Here is a full guide on how to create a setup like that: A General Approach on Building an Approval Process Workflow

Let us know if you have more questions or if you need help with this setup.