Mahalo (thanks in Hawaiian) for your question. Questions like this one are very vital to our salvation and relationship with the Lord. God wants us to know clearly how we are saved, so He sends the Holy Spirit to reveal to us the how, what, and why of salvation. I am going to outline God’s plan of Salvation very briefly, so please, if you don’t understand or need more specific information that pertains to you, please ask.
God created man good with free will (the right to choose). Man sinned (made wrong choices). God requires the sacrifice (shedding blood) for the atonement (making right again) for sin. God came down from heaven and became a human (Jesus) so He could die (shedding Blood) for our sins. Jesus took upon Himself everyone’s (past, present, and future) sins and died, was buried so he could carry all that sin to the fiery furnace (hell), and then God raised Jesus from the dead. Jesus then went to heaven to mediate on our behalf. (Scripture is available for all the above.)
The Bible says in Romans 10:9 and 10 that we need to confess with our mouths that Jesus is our Lord. That means we need to say out loud that Jesus is the absolute boss of our lives. We also need to believe in our hearts that God raised Jesus from the grave. Our belief in what Jesus did for us is what justifies us (makes us right again), then when we speak what is in our hearts (Luke 6:45), that Jesus is our Lord and Savior, we are saved.
Remember, if you don’t understand, ask!