Youcat commented through CCC – Question n. 220.

YOUCAT Question n. 220 - What sort of preparation do I need in order to be able to receive Holy Eucharist?

(Youcat answer) Someone who would like to receive Holy Eucharist must be Catholic. If he has a serious sin on his conscience, he must first make a confession. Before approaching the altar, one should be reconciled with his neighbors.

A deepening through CCC

(CCC 2042) The first precept (“You shall attend Mass on Sundays and holy days of obligation and rest from servile labor") requires the faithful to sanctify the day commemorating the Resurrection of the Lord as well as the principal liturgical feasts  honoring the mysteries of the Lord, the Blessed Virgin Mary, and the saints; in the first place, by participating in the Eucharistic celebration, in which the Christian community is gathered, and by resting from those works and activities which could impede such a sanctification of these days (Cf. CIC, cann. 1246-1248; CCEO, cann. 880 § 3, 881 §§ 1, 2, 4). The second precept (“You shall confess your sins at least once a year.") ensures preparation for the Eucharist by the reception of the sacrament of reconciliation, which continues Baptism's work of conversion and forgiveness (Cf. CIC, can. 989; CCEO, can. 719). The third precept (“You shall receive the sacrament of the Eucharist at least during the Easter season.") guarantees as a minimum the reception of the Lord's Body and Blood in connection with the Paschal feasts, the origin and center of the Christian liturgy (Cf. CIC, can. 920; CCEO, cann. 708; 881 § 3) 2

Reflecting and meditating   

(Youcat comment) Until a few years ago, the practice was to eat nothing for at least three hours before Mass; that was how people prepared to encounter Christ in Holy Communion. Today the Church recommends at least one hour of fasting. Another sign of reverence is to wear one’s finest clothing—after all, we have a rendezvous with the Lord of the world.

(CCC Comment)

(CCC 1416) Communion with the Body and Blood of Christ increases the communicant's union with the Lord, forgives his venial sins, and preserves him from grave sins. Since receiving this sacrament strengthens the bonds of charity between the communicant and Christ, it also reinforces the unity of the Church as the Mystical Body of Christ.

(The next question is:  How does Holy Communion change me?)