Learn About Where You Want to Serve
Where is God calling you to go? Perhaps He has already placed a part of the world, a particular country, or even a specific people group on your heart. If He has not, keep on praying and exploring various cultures as You seek His direction.
If you have even a general idea of where God is calling you, begin to learn more about it. Take an online course about the culture you will minister in. Look for information about the people both online and in books. Read as much as you can about missions work in that part of the world.
Learn to speak the language. Language lessons are available online in a variety of languages, and some of them are free. Even if you do not have time to become fluent, even learning just a few basic words will be helpful.
Use the prayer points in Operation World as a guide for praying for that part of the world. God may reveal to how He plans to use you to help answer those prayers.