Remember that the world in which you leave is a world of darkness.
In this world of darkness, there is a light coming down from the heavens and shining through many lamps. This light is Christ, and the lamps are His little ones, the baptized faithful.
The world promises many things, but they are illusions. For the promises of the world are hollow, like that of Satan promising “all kingdoms of the world” to Jesus, who was the Creator of all things and King of the Universe.
Marriage, like priesthood or religious life, is a vocation. Above all else, we are called to develop the virtue of chastity, which requires an apprenticeship in self-mastery, and will strengthen you against the serious weakness of the passions, forming your conscience and making you grow more mature and more wise, yet more humble and never proud - for by yourself you cannot achieve anything, it is through God that you will grow in perfection.
“Do not worry about tomorrow”, says the Lord. Do the duty that is closest to you. Focus on doing God’s will, on growing closer to the Holy Eucharist - which the saints have called in a supernatural way “the mystical spouse” - both in holy Communion and in Eucharistic Adoration. Do not think of God in terms of “man” - God is perfect, and loves you as a parent, as a brother, as a friend, as a wife.
Learn more about the teachings of the Church on chastity, and especially about the teachings of the Theology of the Body. Learn also - which is very needed in this world - about the different roles of man and woman in the family, because while one is not above or greater than the other, they are not equal; rather, each has a role and a specific authority.
Become more Christlike every day - do not be afraid of imitating Jesus. Think of what would you do if you were Him. Think of what would He do if He were standing right next to you. This may seem simple, but is a very powerful form of meditation that may lead to contemplative prayer.
At 16 you are very, very young, though you may as well have a strong and brave soul, a man’s soul. Trust in God, like our Mother teaches us, kneeling before His wisdom and providence and saying to Him in utter trust: "let it be done to me according to Your word". Do not focus on the past or on the future, but on the present, on the right now, and the Lord will reveal the path to you little by little.
"God is my heaven here on earth. If you would know him enough, you would love him. If you would stay with him for one hour, you would know heaven on earth.
To the extent that we know this God made man, we come to love him madly. I would like you to know him in order to truly fall in love with him…"
St. Teresa de Jesus de Los Andes