J.D.Salinger was a famed author and a recluse. I can;t speak to his innermost thoughts about what he might have had as goals in life, but I can suggest a few things that seem likely.
Obviously, first and foremost, he liked to write, and to write well. After the attention he drew from works like "Catcher in the Rye," he withdrew to an isolated home in New Hampshire. Although he continued to write, he did not publish any more works.
Also, Salinger was knowledgeable about forms of Eastern Religion, like Zen Buddhism and Advaita Vedanta. These religions teach that the goal of life is to free oneself of entanglement in the world, to transcend the world and experience a feeling of ultimate serenity. These are themes in some of his work, such as "Franny and Zooey." In this work, for example, Zooey comments that that are truly beautiful things in this world, and we could see that if only our own egos didn't get in the way. In short stories he also presents Zooey as quipping that everyone would be happier, that the world would be a better place, if we all saw everyone and everything as one, as if we were part of the same whole. These sentiments come from Zen and Advaita Vedanta and probably represent some of Salinger's own thoughts.
Furthermore, in Salinger's most important work, "The Catcher in the Rye," Holden Caulfield is dismayed at the "phoniness" of the world, as if he is himself seeking for something true and real and good. Perhaps, then, we might conclude that one of Salinger's goals in life was to see the world as it truly was, undistorted by his own desires, to see it beautiful in itself.