Past Perfect and Past tense

I'm having difficulty understanding when to use Past tense and past perfect together. For example:

1. I had to do that pose because there were no other poses to do.


2. I did that pose because there were no other poses to do.

Which one is correct? Because of my understanding Past perfect is something that happened before past tense. Example: when i entered the room, she had already left. Which means she had already left before i etered the room.
But in the number 1 sentence it feels so right... I don't know. Please help