All of the points that @Spicy Chickenjoy has stated. As for currency exchange, Check the current rate of exchange online before you go. The exchange locations in the airport offer good rates as compared to sending money to yourself then having to pay the exchange rate plus the fees.
Also, make sure if you plan on using your credit cards out of the country, call or go online to let them know you will be using them and the dates of travel.
If you are 100% sure this going to be your plan (K1). Take all of the K1 paperwork with you. You can go thru the list of things you will need from her, copies of birth certificates, pictures for the application, CENOMAR, etc. This may help and avoid the expense of sending this to you back in the States.
If you are using taxis be sure they are using the meter, some will tell you a flat rate and it will be many times the actual cost if they were using the meters. Best to download GRAB unless you plan on using Jeepneys or trikes. (My 6' - 280lb frame does not fit well in local transportation).
But most of all...have fun, see the country side, enjoy the great food and hospitality.