Learning a new language is very challenging and overwhelming at times, but if you can speak some of the local language it will help you transition to a new culture more smoothly. This is true around the World and Costa Rica is no exception. Although many locals speak some English and I know many foreigners that have gotten by for years without any Spanish skills; I still feel learning some of the language will only benefit you in the long run. The locals will appreciate any effort to learn their language and are very helpful; often times they will want to practice their English while you practice your Spanish.
When I first moved here I enrolled in a Spanish school in Playa Dominical for 3 hours per week and for 3 months total. This was not much in reality, but was a good base and I was constantly practicing with locals and of course my girlfriend at the time, who is now my lovely wife. She helped me tremendously and that is the best way to learn by immersing yourself in the language and speaking it as much as possible. I realize not everyone can fall in love with a local and learn that way, but before moving here you could get Rosetta Stone or go to Spanish class upon arrival. Plus there are plenty of daily interactions and opportunities to practice.
One of the most important aspects of learning any language is to not be afraid to make mistakes and practice daily. True story: after living here just a few months I knew enough Spanish to be dangerous and went to a local store looking for some soap. I proceeded to ask the person helping me if they had any “sopa” (which was my way of saying words I did not know, just add an ‘a’ at the end and it may sound Spanish enough). She then toke me to the soup aisle and I said no, “sopa” and begin to make motions like I was in the shower soaping up. She began to laugh historically and then toke me to aisle with soaps, shampoos, and personal hygiene products. Turns out the word for soap is “jabon” and my made up word for soap, “sopa” was way off and actually the word for soup. But be careful not to ask for “jamon” when looking for “jabon”, because you will get some slices of ham instead of the soap you are looking for. The moral of the story is: if you are too scared of saying the wrong thing, you will end missing chances to practice and learn from your mistakes.
The process of learning Spanish fluently will take a year or even more; so be patient, immerse yourself in the culture, and most of all have fun. And if all else fails know that 90% of communication is non-verbal and good old hand signs and acting things out can go a long way! Feel free to share any funny stories about when you learned a second language!