Circled numbers on guitar sheet

Question

What are these circled numbers?

The finger numbers are next to the notes on the left for sure.

I assumed it to be repeat section markings but there is not repeat.

Answer 1

Those are string numbers. It's fairly standard convention, at least as far as I've seen, to put a circle around string numbers.

So in measure 2—the first occurrence of that notation—you'd play the E on the 2nd string, 5th fret, and the C on the 3rd string, 5th fret.