Hi, I'm trying to delete apps from my macbook pro and I can't do it. What's the trick?

Are you using an admin user account? Only an admin user account can delete or uninstall third party applications.

What app are you trying to delete? You cannot delete any macOS installed Applications installed by default from the factory. The original apps included within macOS are part of macOS and cannot be removed.

If you installed the app from the App Store, then I believe you just need to delete the app like any other file/folder.

If you installed the app by downloading it from a website, then there are two possibilities for uninstalling the app.

• If you installed it by dragging the item to the Applications folder, then you can just delete the app like any other file/folder.
• If you had to run an installer app, then you will need to run an uninstaller to fully remove the app since installers typically place items into system areas. Sometimes the app may include an "uninstall option" on one of the app's menus, or the installer app may be included within the app's folder or app bundle, or you may need to download an uninstaller app from the app developer.

You may need to check with the app's developer for the proper method to fully uninstall & remove their app from your Mac.

Here are two Apple articles with some tips, but keep in mind what I've mentioned above since Apple's information is a bit fragmented:

Install and uninstall apps from the internet or a disc on Mac - Apple Support

How to uninstall apps on your Mac - Apple Support