Thanks for reaching out for assistance. I will gladly help assist you on this.
Adding a Samsung account:
Navigate to Settings, and then Samsung account at the top. Then, enter your Samsung account info to sign in. If you don't already have an account, don't worry. Just tap Create account to make one.
Adding a Google account:
From Settings, swipe to and tap Accounts and backup. Tap Manage accounts, and then tap Add account. Tap Google, and then enter your Google account information to sign in.
When you add your Google account, you'll be able to access emails using the Gmail app on your phone or tablet, as well as use Google apps and Google services.
Adding an email account:
Navigate to Settings, and then swipe to and select Accounts and backup. Tap Manage accounts, and then tap Add account. Tap your email provider and then enter your account credentials. Depending on your provider, there may be additional requirements to complete the setup on your device. If needed, sign into your account via the internet, and then turn on access to allow use of the app.
You can also find these exact steps in this link here: https://www.samsung.com/us/support/answer/ANS00078934/
If you are still having troubles with adding an email, I would recommend reaching out to Customer Service at 1-800-726-7864 for remote support.