2:11 Does this mean that everyone who ever lived has known of God's grace that brings salvation?

No, all men here refers to humanity in general, not every individual ('cp 'Tit 3:4; Ro 5:15; 2Cor 5:19).

God's saving grace, through the atoning sacrificial death of Jesus Christ His Son, has made salvation available to the whole of humanity.

But it only becomes effective to those who avail themselves of it (cp Jn 1:12; 3:16-18, 36; 5:24; 6:40; 10:9; Ro 10:8-10).