How did people and goods travel from venice to damascus and alexandria?

The trading route most likely happen by ships through the Mediterranean Sea.
The only option besde that would be by land. But the distance required to do by land is further than those the sea  and it has to pass the territory of Greece and Turkey, which will guarantee additional toll payment and reduce the traders' profit.

So  if  the sum of the enthalpies of the reactants is greater than the products, the  reaction  will be  exothermic.  if  the products side has a larger enthalpy, the  reaction  is  endothermic. you may wonder why  endothermic reactions, which soak up energy or enthalpy from the environment, even happen