The proper article for would be:
If you're looking for a (the word "the") to use before it in a sentence, it would be: young sheldon s03e08 1080p bluray
(using a capital 'B' and 'R' in BluRay, or "Blu-ray" if you prefer the hyphenated form). The proper article for would be: If you're
Example: "I just downloaded Young Sheldon S03E08 1080p BluRay." young sheldon s03e08 1080p bluray