Here "declare it freely" is a metaphor for telling people in many places about what had happened. Alternate translation: "began to tell people in many places about what Jesus had done" (See: and [[rc://en/ta/man/translate/figs-metaphor]])
This was the result of the man spreading the news so much. Here "openly" is a metaphor for "publicly." Jesus could not enter the towns because many people would crowd around him. Alternate translation: "that Jesus could no longer enter a town publicly" or "that Jesus could no longer enter the towns in a way that many people would see him" (See: [[rc://en/ta/man/translate/figs-explicit]])
The word "everywhere" is a hyperbole used to emphasize how very many places the people came from. Alternate translation: "from all over the region" (See: [[rc://en/ta/man/translate/figs-hyperbole]])