en_tn_lite_do_not_use/rom/01/16.md

I am not ashamed of the gospel

You can translate this in a positive form. Possible meanings are that 1) Paul believes that the gospel is true, and he is not afraid of being ashamed for having believed something false. Alternate translation: "I am completely confident that the gospel is true" 2) Paul believes that the gospel is morally good, and he is not afraid of being deceived into doing evil. Alternate translation: "I know the gospel teaches me to do what pleases God"

it is the power of God for salvation for everyone who believes

Here "believes" means that one puts his trust in Christ. Alternate translation: "it is through the gospel that God powerfully saves those who put their trust in Christ" (See: rc://en/ta/man/translate/figs-explicit)

for the Jew first and for the Greek

"for Jewish people and also for Greek people"

first

Here "first" means coming before all others in order of time.