Moving to Panama without knowing Spanish?

http://yairatutoria.com/  6 months of daily classes with homework, and it was still a struggle when I first arrived (languages are NOT my forte!)  But I managed to get by and little by little it's gotten better. My friends are almost all non-English speaking Panamanians and everyone is super helpful if you are trying to learn. I carried my dictionary with me everywhere for probably 4 years and we'd look up words together when I got stuck.
Kudos to you for wanting to learn. It makes a huge different in your experience here. And they say it's great for your brain, less chance of getting dementia later.

You should really know some basics.  It's not too hard to learn.
Make a mental note of what you say on a daily basis, as you interact with others,
such as going to the store, or going from one place to another.

Numbers, greetings, basic colors, directions, etc..

An on-line app (Babel/Duolingo/et.al) will help build your vocabulary and mechanics, outside of that, there is nothing that beats full immersion.

Don't be afraid to be wrong. 
People will understand your situation and will be more patient and try to assist you, if you're trying.
Don't be frustrated, and treat each encounter as an opportunity to learn.