Hi Barney, just looked at the last game you lost. Game 8576856
Never mind the opening books. Waste of money at your level.
Waste of money at my level. A waste of money, memory and time.
You won't much get theory on 1.e4 e5 2.Qf3 which cost you as Black
a piece after 9 moves. (except in KoKo The Clowns Opening Book.)
2.Qf3 is a clown's move. 2.Qh5 at least has some point though it too is duff.
The clowning days are over.
The new you from on will get the pieces off the back rank ASAP.
If your opponent is not doing the same then you attack him with gay abandon.
Get the Opening Principles about development and control of the centre
off to pat till it becomes 2nd nature.
at 65 You most likely have a chess book or two knocking about the house.
It will explain the principles.
This covers them.
And a couple of vids.
OK let us see how your game should have/could gone.
You were Black.
Now Barney get out there and stop messing about with your h-pawns.
Develop your bits, get castled, throw your centre pawns at him and whack him.
That I believe is two pints you owe me.