There are several ways to produce Sulfuric acid, but here is a list of easy ones:
Sulfur is burnt to produce Sulfur dioxide(SO2). Sulfur dioxide is oxidized to Sulfur trioxide(SO3) with oxygen and Vanadium(V) oxide catalyst. When it is dissolved in Water, it produces Sulfuric acid.
SO3 + H2O ----> H2SO4
Sulfur dioxide gas is passed through strong oxidizing liquids such as Hydrogen peroxide(H2O2) or concentrated Nitric acid(HNO3).
SO2 + H2O2 ----> H2SO4
SO2 + 2 HNO3 ----> H2SO4 + 2 NO2
Reacting Copper(II) sulfate with concentrated Hydrochloric acid produces Copper(II) chloride and Sulfuric acid via double displacement.
CuSO4 + 2 HCl ----> CuCl2 + H2SO4