Roger, I think that because you don't have a location in your profile, people gave you replies that were more applicable in the USA than in the UK.
FWIW I am 71 and use my Kindle in the UK. If you have a wi-fi router, you won't need 3G. Without wi-fi you can still download to your computer and then transfer books by USB cable to the Kindle. You will first need to download
Kindle for PC or Kindle for Mac onto your computer. The advantage of that is that you will be able to read books on your computer as well as on the Kindle itself. Amazon will even synchronise your computer version with your Kindle version (provided you switch on the wireless on the Kindle).
AFAIK the cheaper ad-supported version isn't available in the UK. Library access for the Kindle is going to happen in the USA before it does in the UK, so don't count on it yet.
Do make sure you get a cover for the Kindle. They are a little bit fragile and a good cover provides a reasonable protection against knocks and bumps. And don't drop it in the bath!