As the others have said, Lent is a penitential season of preparation for Easter. As Jesus went into the desert to fast and pray for 40 days in preparation for his public ministry, so too do we seek to prepare ourselves to be witnesses to Christ’s saving Passion, Death, Resurrection, and Ascension.
Often, you will hear of the three traditional forms of penance: prayer, fasting, and almsgiving. “Giving stuff up” is an example of fasting, and that is what most readily comes to mind for most people. But it is just as important to pray and to be generous with others in need with our gifts of material assistance.
Confiteor Deo mentioned the days on which particular forms of fasting are required for all Catholics. That’s our starting point. But it’s good to do more as we are able to. That doesn’t mean we have to fast on bread and water for 40 days. We may decide to go to daily Mass an extra time or two during the week. Or spend a half hour each day reading the Bible. Or donate food and clothing to a food bank. Or stay away from the internet.
There is no love without sacrifice. Whether we sacrifice our time in prayer, our bodily comforts with fasting, or our money with almsgiving—these acts of penance serve to help us grow in selflessness and love and be more like Jesus.