This is the 272nd most frequent Russian word.
пор
"Пор" in Russian is not a standalone word; it may be a root or prefix, or a truncation. If you mean "пора," it means "time" or "it's time."
Here, "пор" is used in the expression "до сих пор," which translates to 'until now'.
До сих пор я не могу решить эту задачу.
Until now, I cannot solve this problem.
In this context, "пор" is part of the phrase "с ранних пор," indicating a start of interest from 'early times'.
С ранних пор он проявил интерес к музыке.
Since early times, he showed an interest in music.
In this sentence, "пор" is part of the phrase "с того пор," which specifies a starting point in time, meaning 'since that time'.