Yes the earliest followers of Jesus continued to worship Yahweh at the Jerusalem temple and to attend synagogue services, but they also gathered together from the earliest days for Eucharist in the context of what came to be called Agape meals.

The distinction between the Liturgy of the Word, derived DIRECTLY from the synagogue using the OT scriptures, and the Eucharistic Liturgy, derived DIRECTLY from the last supper, is found at the core of all early Christian liturgies, all of the earliest rites.