If your video file is named something like Supernatural.S01E01.i-T0AST.720p.mkv , you need subtitles that explicitly state i-T0AST or 720p in their filename. Generic subtitles will drift out of sync within minutes.
A review of the found on Subscene reveals they are a vital resource for fans, especially since some official physical releases—like certain DVD versions —famously lack English subtitle tracks for the debut season. Subtitle Quality and Accuracy i--- Supernatural Season 1 English Subtitles Subscene
Obtain subtitles and episodes from legitimate sources or services that have rights to distribute the show. Avoid unauthorized or pirated content to respect creators and stay safe. If your video file is named something like Supernatural