A) Mass without a Deacon
The Introductory Rites
120. When the people are gathered, the Priest and ministers, wearing the sacred vestments, go in procession to the altar in this order:
a) the thurifer carrying a smoking thurible, if incense is being used;
b) ministers who carry lighted candles, and between them an acolyte or other minister with the cross;
c) the acolytes and the other ministers;
d) a reader, who may carry a Book of the Gospels (though not a Lectionary), slightly elevated;
e) the Priest who is to celebrate the Mass.
If incense is being used, before the procession begins, the Priest puts some into the thurible and blesses it with the Sign of the Cross without saying anything.
121. During the procession to the altar, the Entrance Chant takes place (cf. nos. 47-48).
122. When they reach the altar, the Priest and ministers make a profound bow.
The cross adorned with a figure of Christ crucified, and carried in procession, may be placed next to the altar to serve as the altar cross, in which case it must be the only cross used; otherwise, it is put away in a dignified place. As for the candlesticks, these are placed on the altar or near it. It is a praiseworthy practice for the Book of the Gospels to be placed on the altar.
123. The Priest goes up to the altar and venerates it with a kiss. Then, if appropriate, he incenses the cross and the altar, walking around the latter.
124. Once all this has been done, the Priest goes to the chair. When the Entrance Chant is concluded, with everybody standing, the Priest and faithful sign themselves with the Sign of the Cross. The Priest says: In the name of the Father, and of the Son, and of the Holy Spirit. The people reply, Amen.
Then, facing the people and extending his hands, the Priest greets the people, using one of the formulas indicated. The Priest himself or some other minister may also very briefly introduce the faithful to the Mass of the day.
125. The Penitential Act follows. After this, the Kyrie is sung or said, in accordance with the rubrics (cf. no. 52).
126. For celebrations where it is prescribed, the Gloria in excelsis (Glory to God in the highest) is either sung or said (cf. no. 53).
127. The Priest then calls upon the people to pray, saying, with hands joined, Let us pray. All pray silently with the Priest for a brief time. Then the Priest, with hands extended, says the Collect, at the end of which the people acclaim, Amen.
From: GENERAL INSTRUCTION OF THE ROMAN MISSAL