What must I do to be saved?
First, you must be willing to turn away from your former way of life. Your ability is not required, only your willingness. You must confess that you are a sinner, that your way of life is unacceptable to the Holy God who created you.
"Sin" is an archery term in the days of Jesus. It means to miss the target. We all do that. We also fall short of God's glory. Sin kills us spiritually. Death is not the end of existence. It is to be eternally separated from God.
You must accept Jesus as your only way to be saved. Jesus lived the perfect life that we cannot live. Since we are already dad, we have nothing with which to pay for our own sin. But Jesus is the sinless Man (and God) who obeyed God perfectly. Jesus then offered His own life as the full payment for all the sin of all mankind forever.
Jesus did not stay dead. He rose again from the dead so that we ourselves may have new life in Him. That's the positive side of salvation. The Bible, God's Word, tells us, " ......to all who did receive Him, to those who believed in His name, He gave the right to become children of God—children born not of blood, nor of the desire or will of man, but born of God.…" (John 1:12 & 13)
I won't go into the reason, but God requires a blood sacrifice for sin. Originally, it was the blood of animals. Jesus shed His own blood as the full payment for all our sin. When you receive Christ, you receive what He has done for you through His death and resurrection. It is a wonderful thing to know that your sins are forgiven. I was born again over 50 years ago and I still remember what it was like to know God's forgiveness. It was a great weight off me.
Don't be casual about this. Be real with God because He gave His most precious Son to save you. It's not a mental exercise. It is a lifetime commitment to the true God and to Jesus, who is King of kings and Lord of Lords.