en_tn_condensed/heb/12/02.md

the founder and perfecter of the faith

Jesus gives us faith and makes our faith perfect by causing us to reach our goal. Alternate translation: "creator and finisher of our faith" or "the one who enables us to have faith from beginning to end"

For the joy that was placed before him

The joy that Jesus would experience is spoken of as if God the Father had placed it before him as a goal to reach. (See: rc://en/ta/man/jit/figs-metaphor)

despised its shame

This means he was not concerned about the shame of dying on a cross.

sat down at the right hand of the throne of God

To sit at the "right hand of God" is a symbolic action of receiving great honor and authority from God. See how you translated a similar phrase in Hebrews 1:3. Alternate translation: "sat down at the place of honor and authority beside the throne of God" (See: rc://en/ta/man/jit/translate-symaction)