Is a accepted by all Christians that to attain salvation we must confess that we are sinners and Jesus and to die for our sins and that's it?
In English? No. And lemme explain.
God's expecting a change of heart -- a repentance (e.g., Mt 4:17). That change of heart demands that you
rely on Jesus for your salvation (Rom 10:10). Out of this reliance, you will agree from the heart with God regarding the evil of your sins (Rom 10:10, 1 Jn 1:9a -- the term xlated "confess" isn't simply a verbal confession, it's an admission and agreement), and
turn to Him (Ac 3:19, 2 Pt 3:9).
This in itself isn't something God rewards with salvation, either.
It's not, "Oh, I see you have some faith -- ok, that'll do." Faith is functional. Faith is an instrument God uses in your salvation. He treats you as righteous
through your relying on His Christ, Who really is; God grants you increasingly growing relationship with Him,
adopting you into His family; absolves and resolves the sins that are a barrier to Him; and at the end of this creation, raises you to the new creation.
He promises to finish as strongly as He started.
The net result as you read through Christian writings is that there's a
whole new way to salvation. It's not an equivalent to, "I do something good, God rewards me." It's, "God has detonated salvation in my life through a favor that I don't deserve -- what's the obvious reaction to that salvation?"
Or we must also act upon the word of God? So if I'm a new born again christian and as compared to another that has been born again for sometime now dies at the same time, both of us go to heaven?
"Must" is an ambiguous term. You may do something as a prerequisite to being saved -- that's a "must". But another "must" is that you will do something as a consequence of being saved. Scripture states that the result of the faith that saved is characteristically that you will act on the word of God. And that eventually, the Presence of God with and in you, will inevitably yield to good works.
And what abt the christian that has been born again but is struggling with a sin but he confesseseverytime?does he go to heaven as well if he dies after confession?
I believe you see what would happen in this situation. The person is struggling -- where's that struggle coming from? Is it real, or is it just a "turn of phrase" for someone who's actively engaging in sin and not really struggling with it? That's a question of heart.
God is greater than our heart.