Georgesgran
That’s a yes, yes and yes.
Google insurance for seniors and take it from there, but prices will depend on the state of your health and ages. I wouldn’t take the risk of not bothering.
My Worldwide insurance is with the Post Office. I’m 73.
Some GNs have bank accounts which include travel insurance, with limits.
An GHEC is free and helpful, but doesn’t cover much.
You can pay extra & upgrade, they will screen you for existing conditions.