Most Ticos (i.e. natives of Costa Rica) place a high value on education, 96% are literate. Over the past few decades, the ability to speak English has been a great advantage in the job market, so a very high percentage of Ticos speak some English and an amazing number are fluent. Ticos are famous for their hospitality and kindness, so tourists have very little trouble and don't need to speak Spanish.

If you are going to live here, however, learning Spanish is an excellent idea. Knowing basic phrases before you come will help a lot, and once you arrive there are a great many language schools with reasonable rates to help you progress further.