In general, Costa Ricans are more modest, less assertive, and have better manners than Americans. By the way, Costa Ricans call themselves Ticos, and this term is acceptable for visitors to use as well. Do not wear shorts or revealing clothing while travelling or in San Jose. A skirt is most appropriate in San Jose. Everyone should know at least a few words in Spanish, and you should use them even if you get lost in a deeper conversation.
Toilets are an interesting part of foreign travel.
In general, take advantage of a good one. Also notice that most toilets will have a trash can right beside them. That's where your toilet paper goes. You probably don't want to be the one to stop up the john, so don't forget to keep the paper out of the toilet. If there is not a trash can beside the toilet, assume you can flush the paper.