Languages of interest
Country or region they know well
Countries and regions of interest
Decide why you want to learn a new language. Decide how competent you want to be. Decide what commitment you are willing to make in time and effort. Once those three decisions are clear in your mind, the following necessities will become evident.
To learn a non-native language requires a commitment to yourself to never quit. Make your intention to be able to listen to the news, listen to a movie, and understand 75% of what you hear. Discern the most frequent words of the language, and master them. Let go of your desire to be fluent and knowledgeable in all subjects. It defies the Pareto Principle to try otherwise. And simply not worth it. The ability to communicate, not the ability to educate, should be your benchmark. Efforts beyond that are better placed with the perfection of your own mother tongue.
Good luck, fellow language traveler !