The Liturgy may feel long or unfamiliar, but it shows the heart of parish life. The other services make most sense when they are understood in relation to it.
Why the Divine Liturgy is the reference point
In the Liturgy, the Church hears the readings, confesses the Creed, prays the litanies, offers the gifts, gives thanks, asks for the Holy Spirit, and receives the Body and Blood of Christ. Even if you do not receive Communion, you can see what the Church is ordered around.
This makes the Liturgy a better first reference point than choosing the shortest or quietest service. It gives the whole shape.
When Vespers or Matins may help
Vespers and Matins can be helpful if you want to become familiar with the church space, incense, psalmody, and prayer before attending the full Liturgy. They are real services, not warm-up events, and they prepare the Church for the Eucharistic service.
If a parish has Saturday Vespers, that can be a peaceful first step. Still, return for the Divine Liturgy so the parts are understood from their center.