Full sun....but we don’t know where you live. They are not a windowsill plant.
Hot and dry climates I would say afternoon shade. In mild climates, they can do some shade but won’t flower much.
Let them dry out a little between waterings. Too much water and you get brown/yellow leaf margins.
They hate wet feet...so free draining soil is a must.
Do not cut back to bare wood, you may lose the branch.