Pulling back with your body to hold the warp threads taut, pull the loom card upward, so that the half of the warp that’s threaded through the golden diamonds lifts above the other half, which should drop to the bottom of the blue slots. The space between is called the shed. Leaving a length of weft hanging off, pass the shuttle through the shed. Then use a fork or the loom card to pull the weft toward the stick that you’re tied to.
Continue to hold the warp tight with your body. Reach underneath the loom and pull the loom card downward, so the threads through the golden diamonds dip down below the threads which now rise to the top of the blue slots. Wind more weft yarn off the shuttle, and pass it back through the shed, in the direction from which it came. Again, use the loom to pull the weft toward you and pack it in.
Repeat— you’re weaving! When you’re done, slip the sticks out, knot the warp threads at the weft edge, and you’ve got your cloth to do as you wish. This length makes a perfect scarf.