Which account are you talking about? Log into that account. Then go to the user settings.

Why are you asking "which" account. The account to which I am referring is the account that I use on a routine basis to browse the internet.

I've logged into my account, but do not see any link entitled "user settings".

Mozilla is sub-divided to several separate websites. Each having its own user/password settings.

Mark In Lincoln said

The account to which I am referring is the account that I use on a routine basis to browse the internet.

That is with your ISP (Internet Service Provider). Contact their support for more help on this.

I was able to create a new Firefox profile (account) in about 5 minutes following instructions from "How-To Geek" page on line.

Now I just need some direction on how to transfer my folders, bookmarks, add-ons from my old existing Firefox account to my new existing Firefox account.

Are you talking about the user profile? Firefox sets up a separate profile for each user on the computer.

Last year I changed my email address from a gmail one to a business one that I use for our home business in conjunction with Office 365. I was informed that in order to change an email address in Firefox, I would need to create a new account since the email addresses cannot be changed in Firefox. So now I want to create a new Firefox account with the new email address. I did that following the instructions in the "How-To Geek" page. Now I need to somehow transfer the folders, bookmarks, etc. from my old Firefox account to my new one. I keep on reading instructions that there is a "sync" tab when clicking the menu icon, but there isn't one. I'm using Windows 10.

Firefox, the program, doesn't need or use user accounts. That is why I am asking you what account you are talking about. Is it the sync, support, add-ons . . . . . . . .

I already responded to you comment a few hours ago, to wit:

"The account to which I am referring is the account that I use on a routine basis to browse the internet. "

Please refer to my other responses regarding what I need to do.

Firefox Account = for Firefox services https://support.mozilla.org/en-US/kb/access-mozilla-services-firefox-accounts

Create a new Firefox Account here: https://accounts.firefox.com/signup

As soon as you Sign in to Sync using the new Firefox Account email address and password the Sync process will start on that device. Data from that device will populate the new Sync Account, Similar for each additional device using Firefox & Sync.

There is no way to manually transfer Sync data from one Firefox Account to another; the "source Firefox Sync data" originates from each device when setting up a new Sync / Firefox Account.

Sign in to Sync is available from the Menu Panel that appears when you click the "3-bar" or "hamburger" button on the right-side of the Navigation toolbar. see the screenshot

As far as a "How-To Geek" article about using Sync in Firefox ... http://www.howtogeek.com/105389/how-to-sync-your-browser-data-with-firefox-sync/

That is the first "How-To Geek" article that appeared for me when using Google to search for "How-To Geek" Firefox Sync. All the way at the bottom is says Published 02/13/12 And that's the only "How-to Geek" article I found via that Google search about Firefox Sync; nothing about Sync 1,5.

Firefox 29 with the current version of Sync 1,5 was released on April 29, 2014; that article is about for Sync 1.1 version and isn't applicable to the current version of Sync 1.5.