that is great that you are 83 and working with the latest technology..
and also good that you have your fall back options of asking your younger family members for help!
Have you looked into other accessibility features that the iPhone offers?
here is a good launch point for looking into all the options..
Get started with accessibility features on iPhone - Apple Support
I'm 'young' so I don't really use these types of features..
but there are functions that can magnify your screen as well.
Do you have trouble reading things on your phone?
If you go to Settings > Accessibility > Zoom and turn on the switch, you can zoom in on the screen by double tapping with 3 fingers. You can change it so that it uses a re-sizeable window or the entire screen. There are gestures you can use to change the zoom level, or I find it easiest to triple tap with 3 fingers and it'll bring up a menu for you where you can apply a filter to improve contrast, change the zoom with a slider etc.