In just a few short lines, the speaker describes a small, regular ritual: playing a stringed instrument several times a week. The poem opens with a simple claim, that hands "ought to play," as if play were what hands are naturally for, more than work or gripping or typing. That idea gives the rest its warmth.
The phrase "my instrument and I" sets up a kind of partnership, almost a conversation, and "neck to strings" puts the speaker physically close to the instrument, in a way that feels intimate. The title, "Lessons," suggests the speaker is learning, though the poem never says so outright. That's an inference from the title and the weekly rhythm.
The mood is quiet, gentle and a little tender. Nothing dramatic happens. The short, broken lines mimic the halting, careful pace of a learner, and the poem ends abruptly on "strings," leaving the sound hanging in the air.