There are 2 ways to be notified when someone fills out your Google Form.
In your Google Form, click on the Responses tab. Click on the 3 dots menu and choose “Get email notifications of new responses.”
Google Forms can be connected to a spreadsheet so that all responses from the Form copy to the spreadsheet. Locate the spreadsheet icon on the Responses tab in Google Forms.
From the spreadsheet, click on the Tools menu. Choose “Notification rules.”
In the notifications pop up, select if you want to be notified when “any changes are made” to the spreadsheet or when “A user submits a form.” Additionally, you want to choose how often you are notified; daily or right away.