Your plant is a type of Sedum. The pot is way too big to root such a tiny cutting. The soil is too heavy. It is not getting enough light.
Carefully unpot it and move whatever tiny roots you can find into a 2" pot filled with a porous Cactus potting mix. Then, move it to your sunniest windowsill. Water it only when the potting mix is dry half down into the pot.
