Some translations set each line of poetry farther to the right than the rest of the text to make it easier to read. The ULB does this with the poetry in 1:2-3, which is a quotation from the Old Testament.
Leprosy was a disease of the skin that made a person unclean and unable to properly worship God. Jesus is capable of making people physically "clean" or healthy as well as spiritually "clean" or right with God. (See: [[rc://en/tw/dict/bible/kt/clean]])
Scholars debate whether the "kingdom of God" was present at the time of Jesus or is something that would come later. English translations frequently use the phrase "at hand," but this can create difficulty for translators. Other versions use the phase "is coming" and "has come near."