[Vuejs]-Default select option to first index when populating via array from Vuex store in Vue Component

I suppose you want to select the first project (index === 0) as your default project:

created() {
  this.$store
    .dispatch("loadData")
    .then(() => {
        this.modelCreate = {
            ...this.modelCreate,
            project: this.projects[0]
        }
    });
}