Saved Forever? Repentance? Dreams?

I’m a new believer and keep hearing mixed messages about our security in Christ. Can we lose our salvation or not? When we sin as believers, do we need to repent? My parents have a friend who is constantly having dreams about people dying. How should we look at those dreams?

“Few are chosen”?

What does it mean to “fear the Lord”? How can I share the message of eternal security? What does “many are called, few are chosen” mean? Does our daily “practice” determine our salvation?