When you read a new project you will see a LaunchScreen.storyboard file within your project. This is used to create ‘splash screen’ images for all of the different device sizes that you support.
Simply add your logo to this storyboard and you will see that it will appear when opening your app for the first time.
If you are working on an existing project without this storyboard then you can create a new one and add it to your project. Once you have the new storyboard in your project you can select it by going to your General project settings selecting your newly created storyboard from the dropdown box for the ‘Launch Screen File’ setting.