# the world

In the most general sense, the "world" refers to the heavens and the earth and everything in them.

# since he is Lord

"because he is the Lord." Here "he" is referring to the unknown god mentioned in Acts 17:23 that Paul is explaining is the Lord God.

# of heaven and earth

The words "heaven" and "earth" are used together to mean all beings and things in heaven and earth.

# built with hands

"built by the hands of people" or "that people built"