You can listen to St Mark 1:1-13 read aloud in Latin here and in Greek here. The Latin here is from the New Advent site, which also has the Greek:
Initium Evangelii Jesu Christi, Filii Dei. 2 Sicut scriptum est in Isaia propheta: Ecce ego mitto angelum meum ante faciem tuam, qui præparabit viam tuam ante te. 3 Vox clamantis in deserto: Parate viam Domini, rectas facite semitas ejus. 4 Fuit Joannes in deserto baptizans, et prædicans baptismum pœnitentiæ in remissionem peccatorum. 5 Et egrediebatur ad eum omnis Judææ regio, et Jerosolymitæ universi, et baptizabantur ab illo in Jordanis flumine, confitentes peccata sua. 6 Et erat Joannes vestitus pilis cameli, et zona pellicea circa lumbos ejus, et locustas et mel silvestre edebat. 7 Et prædicabat dicens: Venit fortior post me, cujus non sum dignus procumbens solvere corrigiam calceamentorum ejus. 8 Ego baptizavi vos aqua, ille vero baptizabit vos Spiritu Sancto.9 Et factum est: in diebus illis venit Jesus a Nazareth Galilææ: et baptizatus est a Joanne in Jordane. 10 Et statim ascendens de aqua, vidit cælos apertos, et Spiritum tamquam columbam descendentem, et manentem in ipso. 11 Et vox facta est de cælis: Tu es Filius meus dilectus, in te complacui. 12 Et statim Spiritus expulit eum in desertum. 13 Et erat in deserto quadraginta diebus, et quadraginta noctibus: et tentabatur a Satana: eratque cum bestiis, et angeli ministrabant illi.
From the Douay-Rheims:
The beginning of the gospel of Jesus Christ, the Son of God.  As it is written in Isaias the prophet: Behold I send my angel before thy face, who shall prepare the way before thee.  A voice of one crying in the desert: Prepare ye the way of the Lord, make straight his paths.  John was in the desert baptizing, and preaching the baptism of penance, unto remission of sins.  And there went out to him all the country of Judea, and all they of Jerusalem, and were baptized by him in the river of Jordan, confessing their sins. And John was clothed with camel' s hair, and a leathern girdle about his loins; and he ate locusts and wild honey.  And he preached, saying: There cometh after me one mightier than I, the latchet of whose shoes I am not worthy to stoop down and loose.  I have baptized you with water; but he shall baptize you with the Holy Ghost.  And it came to pass, in those days, Jesus came from Nazareth of Galilee, and was baptized by John in the Jordan.  And forthwith coming up out of the water, he saw the heavens opened, and the Spirit as a dove descending, and remaining on him. And there came a voice from heaven: Thou art my beloved Son; in thee I am well pleased.  And immediately the Spirit drove him out into the desert.  And he was in the desert forty days and forty nights, and was tempted by Satan; and he was with beasts, and the angels ministered to him.
Commentary by Cornelius de Lapide
De Lapide first compares the opening of St Mark's Gospel to that of the other evangelists:
The beginning of the Gospel of Jesus Christ, the Son of God, as it is written in Isaias, &c....The meaning, therefore, is, “The Gospel preaching of Christ had such a beginning as Isaiah and Malachi foretold, that is to say, the preaching of John the Baptist and his testimony concerning Christ.” For John began to preach the kingdom of heaven, that it would be opened by Christ’s preaching and death. Wherefore he urged them to repentance, that they might be capable of receiving the grace of Christ, saying, Repent ye, &c. For Moses and the ancient Law preached and promised a land flowing with milk and honey, if the Jews would obey God’s commandments. But Christ and the Evangelical Law preach and promise the kingdom of heaven, if men will repent of their sins, and obey the commands of Christ. John’s preaching of repentance, therefore, was the preparation for, and the beginning of, Christ’s preaching the Gospel.
Observe, Matthew and John commence their Gospels from Christ Himself—John from the divine, Matthew from the human generation of Christ. Mark and Luke begin with John the Baptist—Luke from his nativity, Mark from his preaching.
On the mission of St John, and the baptism of Our Lord:
For the angel sent by God to prepare the way of Christ was none other than John himself, crying, and preaching repentance, by which the hearts of men must be prepared for the preaching and grace of Christ...John was in the desert baptizing, and preaching the baptism of penance unto remission of sins. That this remission was to be received from Christ and His baptism, which was the perfection and consummation of John’s baptism. For Christ. as it were the King of Heaven, preached that the kingdom must be received by His grace, of which the first part is remission of sins, which is given by the baptism of Christ, inasmuch as it is furnished and, as it were, animated by the Spirit and grace of Christ, according to those words of John (in Matt. iii. 11), “I indeed baptize you in water unto penance, but He that shall come after me is mightier than I, whose shoes I am not worthy to bear; He shall baptize you in the Holy Ghost and fire.”
The temptation in the desert:
And immediately the Spirit drove (Gr. ε̉κβάλλει, i.e., sends out, expels) Him out into the desert. The Spirit, i.e., the Holy Spirit, who a little while before had glided down upon Him in His baptism in the form of a dove. Drove, that is, impelled Christ with great power of spirit and ardour, that He should, of His own accord, go into the desert, and there, as in a palæstra, match Himself in single combat with the devil...And He was with beasts (Gr. θηζίων, wild beasts). This is an intimation of the excessive solitude of the place, as well as of Christ’s innocency. Although He was in such a desert place, with lions, wolves, leopards, serpents, yet He did not fear them, nor was He injured by them. Just as Adam, so long as he was innocent, lived with such creatures without harm in Paradise. For they all looked up to him, and reverenced him as their lord.
And the angels ministered to Him. Not before His temptation and victory, as Bede supposes. For if so, Jesus would have been recognised by the devil as the Son of God; nor would the devil have dared to approach Him. But it was after the temptation and the victory, as is plain from Matt. iv. 11. And for this reason, that Jesus might show in His own person that consolation and comfort and the ministry of angels has been prepared by God for those who overcome temptations.