I’m sorry that you slept through your RCIA classes. Learning about God and the Catholic faith shouldn’t have to be boring!
The sacred liturgy is, above all things, the worship of God. Even if we were to get nothing out of Mass — we were distracted during the readings, or we didn’t understand them, the homily was replaced by a Bishop’s Annual Appeal video, and we did not receive Holy Communion (for whatever reason) — still, vere dignum et iustum est, aequum et salutáre, nos tibi semper et ubíque grátias ágere, Dómine, sancte Pater, omnípotens aetérne Deus, per Christum Dóminum nostrum.*
But there’s more to it than that, of course. Mass has four ends; the acronym “ACTS” or “PACT” has been used as a mnemonic.**
All these ends are directed to the glorification of God: adoration and thanksgiving immediately so, and contrition and supplication mediately, for God is glorified in His mercy and generosity. Those latter two ends are directed toward our sanctification.
To be even more succinct, the Mass and the whole liturgy of the Church is directed to the glorification of God and the sanctification of humanity. That’s what Vatican II said several times:
Christ indeed always associates the Church with Himself in this great work wherein God is perfectly glorified and men are sanctified. (SC 7)
From the liturgy [...] the sanctification of men in Christ and the glorification of God [...] is achieved in the most efficacious possible way. (SC 10)
The purpose of the sacraments is to sanctify men, to build up the body of Christ, and, finally, to give worship to God. (SC 59)
There is hardly any proper use of material things which cannot thus be directed toward the sanctification of men and the praise of God. (SC 61)
The purpose of sacred music [is] the glory of God and the sanctification of the faithful. (SC 112)
* "It is truly right and just, our duty and our salvation, to give you thanks always and everywhere, Lord, Holy Father, almighty and eternal God, through Christ our Lord."
** Another mnemonic, PART, uses "Reparation" in place of "Contrition". Yet another is ALTAR: Adore, Love, Thank, Ask, Repent.