Read quickly, "Trysting" looks like a simple stroll through the countryside. Only the title tells us there is more going on: a tryst is a secret meeting between lovers, so the journey the poem describes is a journey toward someone.
Each stanza moves us along a little further. We pass maples, an orchard and a pond, then drop down to the river, then cross the old bridge, and finally reach the village street at night. The light fades as we go, from bright leaves to "ghost-white flowers" and moths to lamplight in the dark. The scenes are given in short, bare phrases, with no "I" in sight, yet the speaker seems to notice everything, as if each detail were a step closer.
The last line is where the feeling finally surfaces: "a soft step, a sigh, a quickening heartbeat." The mood builds from calm and pleasant to hushed, then to nervous excitement and anticipation.