Follow the way of love and eagerly desire gifts of the Spirit, especially prophecy. For anyone who speaks in a tongue does not speak to people but to God. Indeed, no one understands them; they utter mysteries by the Spirit. But the one who prophesies speaks to people for their strengthening, encouraging and comfort.
First, follow the way of love as outlined in 1 Corinthians 13. More than anything else, as believers, we are called to love. To love God and to love each other. Without love, nothing we do has value.
And, then, eagerly desire gifts of the Spirit. Gifts of the Spirit enable us to be active and productive members of the body of Christ (1 Cor. 12). And that should be something we eagerly desire, to serve those we love and to build them up.
In this passage, Paul compares speaking in tongues with prophecy. According to Paul, both of them have their place. But prophecy is better because of its value to the body of Christ. And, he tells us, we should eagerly desire to have the gift of prophecy.
What is this gift of prophecy? Whatever it is, the one who exercises this gift speaks to people for their strengthening, encouragement, and comfort. And that is something we should all eagerly desire to be able to do. Pray that God would enable you to speak to others in a way that would strengthen them in their faith, encourage them when they struggle, and comfort them in times of trouble. That is a gift we should all desire, regardless of what we might call it.