Yes
They should go every Sunday, and at other times during the week when the Divine Liturgy (mass) is held. Not all Orthodox Christians go each week, but it is a requirement that they should not miss a Liturgy for more than 3 Sundays in a row.
To the best of my knowledge, Catholics do not celebrate length.
Every day of the year 20 or more saints are memorialized.
Catholics must fast on Ash Wednesday and Good Friday under pain of sin. Catholics are encouraged, but not obliged to fast throughout the entire duration of Lent, save on Sundays. On Fridays during Lent, Catholics must abstain from meat.
No. There are 40 days in Lent, not counting Sundays.
According to the Catholic Church, attending the first half of Mass, known as the Liturgy of the Word, is highly encouraged. However, it is not specifically required, and individuals have the freedom to choose whether or not to attend this portion of the Mass. Nonetheless, actively participating in the entire Mass is considered a more complete and fruitful experience for practicing Catholics.
There are three for Sundays and solemn feast days- one from the Old Testament, one from the writings of the apostles, and one from the Gospel. The Second Reading (From the writings of the apostles) is left out on Weekday Masses.
There are many things that Catholics do to celebrate Christmas. They begin their preparation by the season of Advent - the four Sundays before Christmas. Advent is like a little Lent - you are preparing yourself as John the Baptist did for the coming of Christ. One goes to confession to prepare one's soul for the wonder of God coming to earth and into one's life. On Christmas eve one attends the midmight Mass where the Church welcomes the Christ child into the world with hymns and adoration. On Christmas morning the whole family goes to Church to celebrate this most wonderful event. There is a special Mass every day of the Christmas Octave (the eight days of Christmas) and it remains Christmas up through the Epiphany on the 6th of January until the Baptism of the Lord when Christmas comes to an end.
Lent is a time for penance for our sins; however, on occasions of great joy, such as feast days, time out can be taken to celebrate.
Catholics are encouraged to attend Mass every Sunday, as it is a holy day of obligation. Some may also choose to attend Mass on weekdays as a way to deepen their faith and connect with God, but it is not mandatory.
Most Catholics and some protestant denominations as well celebrate lent by sacrificing something they often take for granted. Lent in Christianity signifies the 40 days Jesus spent in the desert.