This article will guide you on how to prevent an application from starting up on Mac startup.
Steps

Step 1. Open the Apple menu
To do this, click on the black icon in the form of the Apple logo, which is located in the upper left corner of the screen.

Step 2. Click on System Preferences…

Step 3. Click on Users & Groups
This icon is at the bottom of the window that opens.

Step 4. Click the Login Items tab

Step 5. Click on the application for which you want to prevent automatic loading at computer startup
Applications can be found on the right side of the dialog box.

Step 6. Click on the button ➖ under the list of applications
This will remove the application from the auto-download list.