Thanks for joining the QuickBooks Community; we're so glad to have you with us. I know life is full of changes, so making changes in your accounts is easy to do. I include the instructions for changing your Intuit account and your company information in your QuickBooks Online account.
When logged into your QuickBooks Online account, one way to update your info is by clicking on the letter in the top right of your screen, then select Manage your Intuit Account. You'll be able to update your information here, or you can navigate to the Intuit Accounts site. You'll sign in with your user ID and will then be able to update your details. You can find this explained in more detail in this link: Change your email, user ID, or password for QuickBooks Online.