The word "we" refers to the disciples and those that witnessed the risen Jesus after his death. (See: rc://en/ta/man/translate/figs-exclusive)
Here, the second word "this" refers to the disciples' speaking in other languages when they received the Holy Spirit.
"Raise" here is an idiom for "cause to live again" (See: rc://en/ta/man/translate/figs-idiom)
To be at the "right hand of God" is a symbol that God has given Jesus greatest honor and authority over all others. The phrase "having been exalted" can be stated in active form. AT: "having been exalted to the place of honor and authority beside God" or "having received honor and authority when God exalted him to the place beside him" (See: rc://en/ta/man/translate/translate-symaction and rc://en/ta/man/translate/figs-activepassive)
Here the words "poured out" mean that Jesus, who is God, made these events to happen. It is implicit that he does this by giving the Holy Spirit to the believers. AT: "he has caused to happen these things that" (See: rc://en/ta/man/translate/figs-idiom and rc://en/ta/man/translate/figs-explicit)
Here the words "pour out" mean to give generously and abundantly. See how you translated a similar phrase in Acts 2:17. AT: "given abundantly" (See: rc://en/ta/man/translate/figs-idiom)