Shalom ! Can you please explain to me the difference between Yetzer (Hara), Sitra Achra and Kelipah ? Please feel free to develop a bit about each term if that’s okay BzH ! Thank you. Kol Tov.

It's a broad topic, for this concise framework. I'll suffice to say that in general, they are similar and overlap, but the term Yetzer Hara (problematic drives) usually expresses the problematic inclinations within a person; the Sitra Achra [literally: the "other side"] expresses those problematic choices as outside a person (a more general, not subjective, issue); and Klipot [literally: peels] refer to when those drives cover up the essential good of the world. You'll notice that Judaism sees the Perfect God's creation as essentially perfect, but part of that perfect world is that He grants us Free-Will. Accordingly, all drives are essentially good, but if man chooses to over-do them, he turns them into bad, (e.g. it's a good and healthy drive to eat or sleep, but if one chooses to over-eat or over-sleep on a regular basis, he turns it into a problematic drive, for him).