All international operators speak English. These calls can be made from private or public phones. Please remember that all calls made with Costa Rica are time charged, including those within San Jose. Mail from the US or Europe can take up to four weeks to be received. The same is true for you outgoing mail to those countries.
Packages can take longer, and many are held at the post office for inspection and taxes or tariffs.
It's best to bring everything you need with you to avoid lengthy waits and expenses. If you wish, you may have your mail sent to the school's address during your stay. It is very easy to find you way around San Jose. Costa Ricans, however, tend to use familiar reference points instead of streets and avenues when giving directions. You might find this Costa Rican custom confusing at first, but with a little patience you'll quickly catch on.