re: First time out of the country, what do I do about cash?

There is some pretty poor advice on this thread. Carrying large sums of cash around is generally not advised due to the theft risk. Same issue with debit cards. They don't typically offer "dollar one" theft protection like credit cards do. Also, if you rent a car or a hotel room with a debit card, they may take a large deposit/hold which ties up your cash.

Take small bills (like $1s and $5s) to pay tips when you get there as needed. Get a small amount of cash from a local ATM when you land and just get more as needed. If you have too much cash at the end, use it towards your hotel bill.

Take a credit card that has no foreign transaction fee. If it as an amex, you can ask them to send you another card with a different number. Carry it separately from the first card and leave in hotel safe. If one gets stolen, call amex and they'll deactivate it. Then use the other. If not an amex, have a second card and carry it separately even if it has a foreign currency fee. This is just a back-up. It is usually good to have at least one visa/MC as not everyone takes discover or amex.

Make a scan of front and back of all cards you are taking and also your passport. E-mail it to yourself (password protect the PDF) or give the copy to a parent or trusted friend in the U.S. That way you can easily cancel the card if stolen or prove to the embassy that you are a citizen to expedite getting a new passport.

Do some research on the country you are going to and see how their currency infrastructure is. Many countries have more sophisticated credit card technology than the U.S. That's good and bad - Australia for example uses NFC widely on their credit cards. So if you have Apple Pay etc, you are golden for literally every purchase unless you are in Uluru or some other outpost and trying to buy local artwork directly from the artisan. Apple Pay is better than a physical US-based card in Australia because US cards are "coded" to ask for a signature and Australians aren't used to that. Many places do not have (or usually need) pens at the point of sale so it slows things down if you need to sign.

In Europe, the default is generally a "chip+pin" credit card. Even if you have a US card with a chip, the default is "chip+signature" which means you can't use a credit card to buy train tickets etc from un-manned kiosks etc because your card doesn't prompt the machine to ask you for a pin. Barclays is one of the few banks that issues US cards with chip+pin.

I'm not sure what the technology is in Colombia, so do some reading up on that.

And to the poster who said Chase doesn't charge a fee to track down Chilean pesos in advance, that is false. It is embedded in the exchange rate. If you asked Chase to buy peso's or sell peso's to you on the same day, the rate would not be the same. They are not just giving you your money in a different currency. They are selling that different currency to you. Compare the rate they offer to the quoted rate on google or any forex site. It will be different. How different points to how much they are charging you. This is also true for ATMs and credit cards, but the spreads TEND to be lower than asking your US bank to track down currency for you, although they will charge you less than an airport forex kiosk etc. My dad likes to have local cash on hand before leaving for a foreign country (despite my advice) and he would get better rates from the Houston branch of his bank than the Baton Rouge branch. It all has to do with volume and which currency you are trying to get.

Lastly and most importantly, if you are using a credit card in a foreign country, make sure they charge you in their currency. Lots of places will try to run your bill in USD as a convenience for you. That defeats the purpose as you are now getting the establishment's exchange rate versus the credit card company's. I've noticed this mainly in Latin countries like Costa Rica, Mexico etc.