This is a dense introduction. How tragic -- these people were 'his own', but they didn't receive him; This world was made by him, yet it did not know him. John 1:12 is a categorical statement about those who did receive him.
"From his fulness we have received grace upon grace (John 1:16)." All the grace we experience springs from Christ. The overflow of his righteousness, love, peace, etc. is the source of our blessings. This places Jesus at the center of our spiritual existence.
The official curiosity about John the Baptist is part of his preparation for Jesus. He garnered enough attention that he could pass it on to Jesus. John denied being Elijah (though Jesus identified him as such), yet he identified himself as the messianic forerunner from Isaiah 40:1-3.