Accessing Microsoft Teams using organizational or personal credentials
Essential is a business plan. If you do sign up for the business plan, it will have you create a new username that ends with onmicrosoft.com. Make sure you write that down because that's your user credential to log into Teams after that. And the subscription will be managed via this link https://admin.microsoft.com.
Microsoft's business and consumer products are from two separate ecosystems. While having the new account will not affect everything on your personal account, however, your Teams signed in with business and personal accounts will run separately, meaning, your existing meetings don't automatically go to your Teams business environment. If you need the meetings to happen under your Essential license, you need to create these meetings all over again in Teams business (signed in with the onmicrosoft.com account).