I repeat: If you hit the Windows Key and start typing just the word Quick then Quick Assist is almost certain to be the first item returned in the search.
If it's not, then just find it in the search results and once you have focus on it hit Enter, this will begin the process of asking for help or offering help. You, of course, will be asking for assistance and your assistant will be offering assistance. You will get a 6-digit (I think it's 6-digits) code that you must provide to your assistant and they enter it on their Quick Assist session to establish the connection to your machine. You will then be prompted telling you that they either want to share your screen or remote control, and you must consent before they get it and can see anything.
Brian - Windows 10 Home, 64-Bit, Version 1809, Build 17763
Explanations exist; they have existed for all time; there is always a well-known solution to every human problem — neat, plausible, and wrong.
~ H.L. Mencken, AKA The Sage of Baltimore