Of course you can delete your account if you wish to. GDPR gives everyone the right to be forgotten.
If you just want to unsubscribe from emails, you can do so in your account settings. Just log in, click on your name in the top right, and click Settings. On the right side, you see Notification Preferences, where you can disable emails.
To delete your account you must first make sure to not be the owner or admin of any company. If you're the only owner, you can transfer ownership rights to another person on the Stakeholder page, or delete the company entirely on the company settings page.
If you're not the owner or admin of any company, a button Delete Account appears in the danger zone of your personal settings. To reach the personal settings, just log in, click on your name in the top right, and click Settings.