You forward emails between different email accounts. Thunderbird is email client software not an email account. What are you trying to accomplish?

rguillaumin said

I want to have other emails forwarded to Thunderbird. Where do I go to do that?

I have 3 other email accounts; hotmail, gmail, & centurylink. I want all of them to be forwarded to to Thunderbird.

Like I said before you do not forward emails to Thunderbird. You enter the details for your email account so it can contact the providers server and check your mail.

I assume you have Thunderbird installed. If not, that would be the first step. You will be prompted by the install wizard for the account details. For the next accounts you click the Menu Button (3 horizontal lines) then click New Message and then Existing Mail Account.