I don't know what I'm doing!
First of all, it looks to me like this plant is not getting enough sunlight. Jade plants like to be in full sun or possibly a bit of shade but they will grow best in real sunny location in your home. That will allow the stems to become much stronger and sturdy enough to allow the plant to grow more upright like it should. The soil also looks pretty loose and dry. Water a jade plant so that you saturate the soil, then allow it to dry out before you water it again. As long as it is a well-drained potting mix and the pot has drainage holes in the bottom. Also, do not allow the plant to sit in a water-filled saucer after watering.
As for pruning, you can cut back Jade plants pretty severely and they will regrow very easily. So in this case, I would cut back the stems that are hanging down below the rim of the pot. (You can then use the shoot tips as cuttings to start new plants. Just remove the lower leaves, let them dry out for a week or so, then stick them into potting soil in a new pot.) This will encourage new shoots to grow upright once you move the plant to a sunnier location.