What is the christian belief about the trinity, the resurrection, and salvation

The Trinity is the three parts of God, the Father, the Son, and the Holy Spirit.
The resurrection is referring to the resurrection of Christ. He sacrificed himself on the cross and rose from the dead in three days.
The salvation is referring to when Jesus died on the cross, he died for all of our sins, so if we give our life to God he can forgive us of all of our sins.