People see wrong name when I send them an email

Hello, I need some help with my email. The problem could either be through Yahoo mail or iCloud. I've already tried looking entirely through Yahoo settings and everything seems fine and has my actual name everywhere. I believe the problem comes from iCloud through the process of elimination, so here I am. I also have gone through iCloud, but it's not exactly the most user-friendly. It's hard to access everything. So, I think I missed something and that could be it to fixing my problem.

Problem: When I send emails, people see the sender as a completely different name than my actual name. When they respond, they always say the same name "Marco last name". It's completely different from my actual name. I know for a fact I did put this name myself at one point when I was a kid when I first created an Itunes account because at the time I wanted to be safe and not put my real name. Now, I can't figure out how to change it to my actual name.

I recently tried searching up all I could to fix this on iCloud and I thought I found a solution, but it turns out my friend still saw "Marco" when I sent him an email after I "fixed" it.

Here is what I recently did:

• On my iPhone, I went on the "settings app"
• Clicked on "Apple ID" at the top of the settings
• Clicked on "iCloud"
• Scrolled all the way to the bottom and clicked on "Mail"
• There it was. Under "iCloud Account Information" in "Name" my name on there was "Marco last name". I immediately thought this was it, this was my problem and I can finally fix it here. I changed my name from "Marco last name" to my actual name.
• Then I Immediately told my friend about it and sent him an email to verify if it worked and my actual name shows as the sender instead of "Marco last name". When he got the email he told me it still shows as "Marco last name" as the sender.

So yea, my problem is still here. I need help to fix this. I thought of something just now, let me know what you think. How about if instead of scrolling all the way down to the "mail" section in the iCloud settings, I go under "Apps Using iCloud" and turn off the "Mail" section. I'm guessing it would make me no longer get emails from my iCloud account, but it could also fix the "Marco" name problem. Let me know what you think about that or anything else I can do to fix this.

Thanks,

Mark