Jesus then went to the Sea of Galilee (or the Sea of Tiberias) and had many people following Jesus because of the miracles Jesus did. He also spent time with the disciples on a mountain.
Eventually, Jesus saw multitudes coming to him, likely because of hunger. However, Jesus has a plan. Even then, he asked Peter where to get food -- but the purpose is to "test him" (6:5-6). Sometimes, school teachers ask questions on concepts that the school teacher already knows (obviously), with the purpose to get students to see what they know or need to review. In a similar way, Jesus's "testing" is likely regarding faith in Jesus to get seemingly impossible tasks done. He also opened up a conversation with the disciples regarding getting food for the multitudes.