I'm doing this an answer because it seems there are no one from Costa Rica and I think now is better to help instead of doing a perfect answer, also it doesn't fit in a comment.
First, Carlos Alejo and guifa gave good points in the comments, to specify the type of connection you are searching would help, and guifa gave you specific advice about the country.
As far as I know almost in all South America usted is used not only for formal relations, sometimes even conjugating the verbs with the second person both singular and plural, instead of using the third person. There are significant differences between countries though, so if there's no one from Costa Rica that can help you here, I'd try to observe how others in that country speaks to their relatives, your coworkers, a mother with her child in the street, that type of things.
You can directly ask someone in the same country too, you know, in the shop you buy the food, to your neighbour, one of you co-workers. I'm sure that you'll find people that will help you with it. Use usted to ask it so you ensure that you ask it politely and you'll be ok.
I've visited different countries in Europe and South America and I have never had problems asking that type of thing. Nowadays people are generally used to see and "coexist" with tourists, if you choose someone who know who you are (like a co-worker or a neighbour) or someone that his/her daily work is to speak with others (clerk, shop assistant) and of course you are polite (use usted), you will most probably be gladly answered.