Spanish
The majority of South America speaks Spanish, so if you want to check out those countries, then that’s the first language you should learn. It will also help you when you travel to Europe as many people make a visit to Spain. Spanish speakers are found almost all over the world, and having this in your repertoire will go a long way to getting around.
Mandarin
Mandarin is very useful to have if you intend on visiting Asia. It is spoken in more than one country, which means learning it will be helpful in multiple places. Countries like Singapore and Malaysia use Mandarin in their everyday language, and you’ll likely come across someone who speaks Chinese anywhere in Asia.
English
English is spoken in so many countries, so it’s essential for traveling. It’s widely spoken in North America, the UK, as well as Australia and New Zealand. Those are all hotspots for travelers, but English will also help you out across most of Europe. It’s spoken as a second language by many people on the continent and having a bit of English will help you get by almost anywhere.
Learning an extra language can be so helpful when it comes to traveling. You can communicate better with the locals and enjoy more of the wonderful experiences those foreign lands have to offer.