It is in first person. That, however, does not tell us anything about whether Poe himself had a dead girlfriend named Lenore (or anything else). The speaker of a poem -- the character in the poem who calls himself "I" and "me" -- is not necessarily the same person as the real-world author. The speaker can be a totally fictional character. Robert Browning wrote a poem in first person in which the speaker confesses to having killed his wife. But Browning himself did not, actually, kill his wife. (Also, the guy was a Renaissance Italian duke, and Browning wasn't any of those things either.) It was a totally made-up story.
If you read it you will see. If you can't work it out you are on the wrong course.
