First of all, you should say the statement below rather than the below statement.
"Not Everything is meant to be." In other words some things are just not going to happen, in spite of our best efforts.
"But everything is worth a try, especially in terms of a relationship." I'm pretty sure that the author had used relationship in the sense of a romantic relationship. So if you are attracted to somebody, you should try anything you can think of to get closer to that person.