Can I have more than one account in the wallet?

Yes, if the wallet came from a seed phrase. Each extra account is a fresh address derived from that same phrase, which means one backup still restores all of them — there is nothing extra to write down when you add an account.

Add them from the account switcher at the top of the home screen, or from Settings → Manage accounts. Names are up to 25 characters and are stored only on this device, so renaming an account changes nothing on the chain.

Accounts you are not using can be hidden, as long as one stays visible. A wallet imported from a private key has a single account and no account management.