# A vision appeared to Paul

"Paul saw a vision from God" or "Paul had a vision from God"

# calling him

"begging him" or "inviting him"

# Come over into Macedonia

The phrase "Come over" is used because Macedonia is across the sea from Troas.

# we set out to go to Macedonia ... God had called us

Here the words "we" and "us" refer to Paul and his companions including Luke, the author of Acts.