That’s what I would suggest too. I’m your age and have been riding regularly (this time) for about three years. My neighborhood is safe enough for riding and 7 miles seemed like a good accomplishment. Then it was regularly 10, then 15, now even a “quick neighborhood ride” turns into 2 hrs and 20 miles plus. And driving to more interesting terrain and roads or bike trails adds more enjoyment.
And as others have suggested, make sure you keep it enjoyable. For me, that pretty well equated with longer.
The suggestion of turning around t the end of the loop is also good. I find out and back is not redundant at all; going the other way presents a different views, climbs, etc.