I was there with Marco, my best friend.
I = first person
other possibilities:
he/she/they/name (no I, usually) = third person
you = second person (very rare, mostly limited to interactive novels)
was/were = past-tense
other possibilities:
am/are/is = present tense
The most common types of narration are third-person past, first-person past, and third-person present:
3rd past: Jake was there with his best friend, Marco.
1st past: I was there with my best friend, Marco.
3rd present: Jake is there with his best friend, Marco.