What is the Gospel from Jesus? Is it the Gospel by Jesus means the same thing?

There is no Gospel by Jesus. The Gospel writers (Matthew, Mark, Luke, John) wrote about the life of Jesus. Gospel means good news. It is a specific good news from a definite source about a particular subject. It is, in fact, a message that God has appointed to be announced to all mankind.
the Gospel is closely linked with Jesus Christ—so much so that the four Bible accounts of his life on earth are called the four Gospels. Right from the beginning of his human life, news about Jesus was good news. When announcing his birth, an angel said: “Look! I am declaring to you good news [or, gospel] of a great joy that all the people will have, because there was born to you today a Savior, who is Christ the Lord.”—Luke 2:10, 11.
The newborn Jesus would grow up to be the Christ, the promised Messiah. He would reveal God’s purpose for salvation, give up his perfect human life in behalf of mankind, be resurrected, and then become the chosen King of God’s Kingdom. Good news indeed! That is why the message about him is called the Gospel.