Did Cuneiform consists of symbols to make groups wedges and lines?

That's exactly right! Cuneiform writing is characterized by its use of wedge-shaped marks, called cuneiform signs, created by pressing a wedge-shaped stylus into a clay tablet. These marks were combined in various ways to form symbols representing syllables, words, and even entire concepts.

The term "cuneiform" itself comes from the Latin word for "wedge-shaped."

So, your understanding is accurate: Cuneiform writing is all about using wedges and lines to create its unique system of symbols.