What might explain the friendly reception both Cartier and Verrazano received from the Native Americans they encountered?

Their intentions were different.

Explanation:

Whereas the Spanish came with clear intentions to conquer the territory and take over Native Americans' lands, the French and the Italian sent their explorers with other purposes. Of course, they also wanted new territories, but they didn't try to take them by force.

Instead, they brought a lot of things to trade with the Natives, and were ready to negotiate, which is why Cartier and Verrazano were received differently.