Outlook question, I need help [View all]

Do I need Windows 11 to download the new Outlook format?

I am not computer literate and usually have help with questions. The person I used is no longer working with individuals, he has gone "corporate. I lave left messages and there is no reply. There is no other repair shop and I can't carry this old Dell to the car and drive.

There are no real directions on the outlook notification. Just "download". What am I going to face. I got the notice on the day after Thanksgiving and have not done anything with this change. Not sure what happens after the download. I don't need all the fancy options, just the basic old "Hotmail".
Can you tell me what I face

Windows 10 OK?
What happens after I hit Download"?

Forgive this old timer but I'm stuck with no knowledge and no ability or $$ to take this computer to a shop,
Thanks for any help you can give. I Googled but cannot find any answers.