Accept that it is a big planet and it is not the same everywhere.
That can be the road you travel on. The place you get something to eat and on and on.
EVERYONE does not speak English. GET OVER IT. Central America is many different countries, Suggest you get out a map and learn a little about the COUNTRY you are going to. Maybe look for some interesting things you might want to see near where your family lives.
Does it not occur to you that your family might have some ideas of things to do for you while you visit.
You can check for basic information here.
WHAT TO TAKE??
Most will take some gifts. AVOID FOOD ITEMS. Check with the country of choice what things they allow you to take in without paying import fees.
See if your Bank card will work in your destination. Not a good idea to have ALL your money in CASH.
The country has their own currency. Good Idea to have some for your first day in cash. The equivalent of $1-200US. This is for the little things you might need when you first arrive. Maybe a soda, a taxi or whatever.
I suspect you might speak Spanish. Good for you it will be very well used.
You make two weeks seem like a you are moving and out of "civilization" for years. It is a vacation. GO HAVE SOME FUN.
You are a person YOU ARE NOT THE UNITED STATES GOVERNMENT REPRESENTATIVE that is the Ambassador. You be tourist and enjoy your time in some other place.
Suggest you pack some sun screen, bug spray and a good pair of walking shoes. Tourist walk a lot. A paper map of the area might be a good idea. Important phone numbers of people there.ON PAPER your gadget might have low battery or just not work in some places.
KEEP YOUR PASSPORT SECURE it worth thousands to criminals. HAVE FUN, EXPLORE and LEARN about some other place.
It is big planet you will never see it all. About 200 countries you are taking the First step to ONE of them.
About 2/3 of US Citizens never leave the USA. They really do not know much about other places. You will see, hear, touch,smell and taste stuff. Some pleasant some not. JUST DIFFERENT and something you do not get watching a video.
THEY HAVE LAUNDRY in other places. It is two weeks you do not need a different set of clothes for each day. Pack things to mix and match for different looks if you want. LEAVE some space in your luggage for the stuff you are bringing back.
Your are a visitor to this place. BEHAVE. Laws are just different in other places and the laws apply to you while in their country.
Suggest you ask your hosts where the good places to wander are.
Do they live in a city? a small town? or a rural place? Will they meet you at the Airport? IF NO how is it you plan to get to them? Bus taxi or what?
Taking your electronic gadget . Do you have a phone plan for this place? It can be expensive if you have a phone that is always on surfing the web. Do you have a charger that works for the electrical system of the place? You may need an adapter to use the local electrical plug.
Suggest you increase your communication with your hosts on stuff you might do and things you may see.
You are a guest a visitor you are not staying in a HOTEL do your part of the house chores.FREELOADERS are not well remembered.
Watch your money. No need to spend it all the first few days.You want to have some for that last day thing too.
Go with the flow. Things are just done different. YOU DO NOT HAVE TO LIKE IT.
Central America consists of seven countries: Belize, Costa Rica, El Salvador, Guatemala, Honduras, Nicaragua, and Panama.
Next year you might visit again or go some other place to see what some other country is like. Maybe even one that is not Spanish speaking. Nice to go in winter to central America for the warmer weather.
If you want more specif answers then give more specific information.
Check the forecast just before you go and see that you pack appropriate things for the expected weather.
It is good thing to depart leaving your HOSTS something special for them.