# There he met

Possible meanings are that 1) Paul happened to find by chance or 2) Paul intentionally found.

# a Jew named Aquila

Here the phrase "a certain" indicates this is introducing new person in the story. 

# a native of Pontus

Pontus was a province on the southern coast of the Black Sea.

# had recently come

This is probably sometime in the past year.

# Italy

This is the name of land. Rome is the capital city of Italy. 

# Claudius had commanded

Claudius was the current Roman emperor.