Both instances of the word "you" and the word "yourselves" refer to the Jews to whom Paul is speaking and so are plural. The word "we" refers to Paul and Barnabas but not the crowd that was present. (See: [[rc://en/ta/man/translate/figs-you]] and [[rc://en/ta/man/translate/figs-exclusive]])
This can be stated in active form. "Word of God" here is a synecdoche for "message from God." Alternate translation: "that we speak the message from God to you first" or "that we speak the word of God to you first" (See: [[rc://en/ta/man/translate/figs-activepassive]] and [[rc://en/ta/man/translate/figs-synecdoche]])
Their rejection of the word of God is spoken of as if it were something they pushed away. Alternate translation: "Since you reject the word of God" (See: [[rc://en/ta/man/translate/figs-metaphor]])
"we will go to the Gentiles." Paul and Barnabas were implying that they would preach to the Gentiles. Alternate translation: "we will leave you and start preaching to the Gentiles" (See: [[rc://en/ta/man/translate/figs-explicit]])