If you're interested in watching the show, I recommend checking out official streaming platforms like Disney+, Amazon Prime Video, or purchasing individual episodes on iTunes or Google Play.
Avoid illegal torrents at all costs. The $20 you spend supports the cast, crew, and possibility of more Marvel television content in the future.
If you want to own the digital files forever (via cloud library), Amazon offers Season 1 in HD.
The first season of Marvel Agents of SHIELD consists of 22 episodes, which aired from September 2014 to May 2015. The season introduces the main characters, including Phil Coulson (Clark Gregg), Melinda May (Ming-Na Wen), Leo Fitz (Iain De Caestecker), Jemma Simmons (Elizabeth Henstridge), and Alphonso "Mack" Mackenzie (Henry Simmons).