It means that you register a profile at free pen pal websites, other people found interested in you, they contact you to make pen friends.
Looking for pen pals online saves us time and money because there are many free pen friends at these pen pal sites to make friends with.
If you're more of a beginner, or if your second language skills are rusty, you'll probably benefit more from starting with an email exchange, where you can take your time reading and writing, looking up words, and asking questions.
To start, you need to find a penpal (or penpals) from the sections above - a native speaker of the language you are practicing who also wants to practice through an email exchange.
Some can and will be a little different, and that is ok. Christian pen pals are people who believe in this religion.