My situation, earlier this year, was similar to yours. I started biking again in April at age 60 after many years away from bikes.
My research led me to buy Sandals and combination platform / spd pedals.
Here is what I bought and am very happy with:
Shimano SPD Cycling Sandals - SH-SD65
Shimano PD-A530 Clipless pedals dual purpose SPD
I can pedal a bit "unclipped" on the platform side of the pedals and then turn them over and clip in.
The sandals are really really comfortable. In the summer I wear no socks, but now the weather is a bit cooler I am wearing socks with them. The straps of the sandals adjust easily to accomodate the socks. There are some cyclists who wear them year round. In the winter they wear wool socks with seal skins to keep their feet cozy.
Good luck.