To use the native G Suite mail, contacts, and calendar apps on your Android, you need to add and then sign in to your new G Suite account. You only have to do this once:
Navigate to your Settings Gear.
From there, select Accounts > Add account (bottom of screen), then choose Google to add your G Suite account.
Now that you've completed your log in, find and open your Gmail app. (Note: to download additional google apps, check out your app store)
From here, you can easily switch between your Google accounts using the ☰ in the upper left corner. From here you can
Note: If an app isn’t already installed on your device, such as Google Drive or Google Keep, search for it on Google Play. All G Suite apps that come with our G Suite account will be free for you to download.