What if I don't eat processed food ; would it be enought ?

Yes, the body regulates its salt balance.  If low the body conserves salts.  If high the body eliminates them.

I mean :

If I undertand well; the sodium in foods is actually sodium chloride, right ?

In processed foods the sodium is primarily sodium chloride or sodium bicarboante.  In natural sources it can occur as sodium chloride or other salts such as carbonate.

Also potassium containg foods is usually chloride potassium ?

Potassium chloride, yes, or other potassium salts such as potassium sodium  tartrate.