Your question is too broad. I'm afraid there isn't an easy formula for learning all abbreviations; besides, some words have multiple possible abbreviations. The only way to learn abbreviations is to learn them one by one.
On-line dictionaries can provide some clues. For instance, the page for international at Merriam-Webster on-line has a link for Ajou Int'l Business School. But as I noted, there isn't a hard-and-fast set of rules for abbreviating English words.