Where can I find The Blue ring in Legend of zelda?

I would assume you're talking about the first quest. If so, from where you start the game, go up one screen, left 3 screens, and up 3 screens. When you get there, you'll need to touch the middle statue in the higher row. This will reveal a staircase that will take you to the shop where you can buy the blue ring for a whopping 250 rupees.

As for the second quest, from where you start the game, go right 4 screens, up two screens, right two screens, up 4 screens, and right two screens. This will bring you to an area with a bunch of peahats (those floating things that are only vulnerable when they stop) and some green trees, one of which you can enter to play the money making game. You will actually have to walk through the wall to the north (not certain of which point, but it's near the open tree.) and you will find a cave you can enter that contains the blue ring shop. This same cave contains a 100 rupee bonus in the first quest, so you should come here in the first quest, as well.

Anyway, I hope you find this info helpful and good luck with the rest of your game!