Is There any way to Potassium Niterate out of Potassium Chloride.

Mix it with silver nitrate (other metals will work too)

KCl + Ag(NO3) → AgCl + KNO3

 

:edit: AgCl will be the solid and potassium nitrate will be the liquid I believe

Is There any way to Magnesium Salfate out of Magnesium?

I think you mix it with sulfuric acid.

Anything Practical

What would you consider practical? You're gonna need some form of every element in the chemical equations and you won't always have them on hand. What chemicals do you have access to? You will most likely need to order some.

very very very little

You can just buy Magnesium sulfate, rather than make it from its constituent parts...

Is There any way to Magnesium out of Magnesium Salfate?

If you want useful answers, be more specific. Of course from any magnesium compound you can obtain the magnesium, but the effort required to do so may be very high.

 

In general, making magnesium out of its salt, is VERY hard for a simple home-lab. You need very high temperatures and/or a very strong reductor. Using molten MgCl2 (made from MgSO4 by precipitation of Mg(OH)2 with NaOH and then dissolving the Mg(OH)2 in dilute HCl and then evaporating to dryness) probably is the easiest way, but I promise you, this will be next to impossible also at home without the proper equipment.

 

So, practically speaking I would say: NO.

You could find sulfuric acid in car batterys but I dont think that it is very pure.