I need to upgrade my browsers BUT first must upgrade my OS -- I was told by Apple geniuses I myself can actually upgrade BUT I suggested to them, "what happens if I'm confronted with a glitch or a problem I cannot solve?" -- They suggested they can upgrade for me -- I was also told the charge for this service was "nothing" -- Does all this sound correct to you? -- I want to make an appointment with the MAC people but I want to ensure I spoke with someone who relayed their "Apple policy" to me and NOT some personal agenda of a particular salesperson. -- PLEASE ADVISE ME!

You need a good dose of bravery.
Confronting a glitch while upgrading your OS is no worse than stepping out of your house when it might rain.

As for what they told you - it's all true. After all, Apple is in the business of selling or giving Apple products to happy Apple users.
But why not take pride in what you can do on your own?

Thank you much, Joy.

Will take your advice.

In the event I choose to use Apple geniuses, by the way, how are my data and files kept from being violated? e.g., how do I know that someone won't abuse the info they may see on the screen?

You don't know. But unless you are famous or infamous, no one cares, they have jobs to get done, and they have jobs they want to keep, presumably.

Think of it this way: your computer files are at risk every single second that you are online.

Got it! -- I, for one, surely would not care! -- So, it's highly likely that you're correct.

Again, thank you, Joy. -- Great help!