Please address yourself in English because this is the international community, there is also for other languages, I say it with respect. As for altar you can have as many as you want and do as much as you want in them, you don't always have to take them off after a work or something if you don't feel like it.
You can also do the material one or/and the spiritual one.
How? As you want, it can be anything you want it to be, it's your own personal space which only you will be using to do stuff , so yea, you could do one for black magick one for white magick as is not good to have just one for the same cause , that applies for rosary's as well!