Recently, a client asked me for a help with registering a domain name in Bluehost. He signed up for Bluehost's Shared Hosting plan but entered a wrong email address during sign up process.
The problem was that he registered a domain name but could not verify his email address because he entered an incorrect email address.
ICANN (Internet Corporation for Assigned Names and Numbers) requires validation of the registrant WHOIS contact information whenever you register a new domain.
When you registered a new domain name during sign up process, the domain name will appear under Domain > My Domains.

If you have not verified your email address which was used for registering a new domain name, a warning message is displayed: "Site will go offline in 15 days." You need to click a link contained in a verification email to verify your email address. If you have not received a verification email, you can click the button "Resend Verification Email."
If a wrong email address was entered during sign up, you first need to update your email address for your Bluehost account. You can update your email account for your account on the Profile page.

Then, you need to modify registrant email address for your domain. Click "Manage" indicated below under Domains > My Domains.

Here, you can modify your email address for your domain.

Please click "Contact" and "Edit" next to "Registrant" to modify registrant email address.
After updating your email address, please contact Bluehost via Live Chat. If you let them that you modified registrant email address because you had entered a wrong email address, they will check the issue and update it within 2-3 days.
Just for your reference: if you wanna a cheap but relatively good performance (cost-effective) web-hosting service, you might consider Bluehost’s Shared Hosting. Most especially, if you sign up for BH Shared Hosting plan by clicking on this referral link, you can get one dollar discount per month.
If you purchase a web-hosting service by clicking on a link contained in this article, I will get some commission. However, I do not recommend a specific web-hosting service just for commission. I have been managing several WordPress sites from different web-hosting services including Bluehost and SiteGround for years.