What were the goals and outcomes of the U.S., the Philippines, and Puerto Rico in the Spanish American war?

The United States had a number of goals in the Spanish American War. The most heavily advertised goal was humanitarian. For several years, the Cubans had been fighting a war for independence from Spain. When reports of mistreatment of the Cuban people reached the United States, there was an outcry by many to intervene. Many US newspapers regularly published stories meant to drum up sympathy for the Cuban people in the years and months preceding US involvement.
There were also less altruistic motives of the United States. There were many in the US who wanted to expand the country's overseas holdings. Spain was weak and struggling to hold on to its far-flung empire. There were opportunists in Congress and elsewhere who saw war with Spain their chance to grab some overseas real-estate.
With these aims, the United States was successful in achieving its goals. With the signing of the Treaty of Paris, the Cuban people gained their independence and the United States received several former Spanish colonies in the Caribbean and the Pacific.
The Philippines were caught up in the war quite by accident. When Commodore Dewey defeated the Spanish naval forces at Manila Bay, many Filipinos were torn as to whose side to support. Even though the Philippines had fought a series of rebellions against Spanish rule, they were currently under a truce. Dewey increased his odds by transporting exiled Filipino rebel leader, Emilio Aguinaldo back to the islands. With the support of the United States, Aguinaldo declared independence from Spain and resumed his fight. While their goal was independence, in the end, they were betrayed when the Philippines were ceded to the United States at the end of the conflict.
Puerto Rico had long been a poor and almost forgotten part of the Spanish Empire. The Puerto Ricans never had any real hopes of independence as a result of the conflict, but many hoped that they would receive more rights and see more development in their economy under US rule. The Foraker Act, passed in 1900, gave Puerto Ricans limited local autonomy although most officials were appointed by the federal government. The United States helped Puerto Rico develop infrastructure and educational facilities. In 1917, Puerto Ricans were granted US citizenship. However, many Puerto Ricans were continually frustrated at the lack of independence they had.
https://history.state.gov/milestones/1866-1898/spanish-american-war