Hi,
When we deal with one single event that occured in a specific time in the past, use the simple past tense.
We use 'past perfect' to show sequence of events that happened in the past. Given two events,
A and B, both happened and were over in the past, A first then B - we
use the simple past tense for B and the past perfect tense for A.
(Think of 'past perfect' = 'past of past').
Now look at both of your sentences, without other event mentioned to help us establish a time sequence, we should use the simple past tense.