I have my padi card, but gave up scuba a few years ago, to much work, sometimes. As for the snorkel and age, if you can still swim and don’t panic - go for it. My husband had a panic attack in six feet of water, while snorkeling with me. He needed to swim 5 feet in any direction and would be able to stand, however he wanted me to save him. I wasn’t planning on drowning that day and screamed at him to jump in any direction and stand up. He finally did, I than marched him out of the water and he sat down on the beach. Needless to say, he doesn’t snorkel any more.
I’m 64 and have done lots of snorkeling without a vest, noodle, etc with just my dive flippers. As I get older, the flotation will be added. Go have fun.