No. A clip is published work. A pitch is an idea for a story that hasn't yet been accepted by a publication. Two entirely different things.

I'd suggest you start by learning the vocabulary of the industry, sharpening your writing and reporting skills and reading many, many back issues of publications where you think your work might be a good fit. Assigning editors prefer writers who are familiar with their editorial preferences. One way to get off on the wrong foot is to pitch something they've done recently (or even within the past couple of years). And it helps to pitch in the style of the publication. A pub that leans toward short, practical self-help with snappy, trendy writing isn't going to be interested in a long, introspective piece with lush writing.

Pitches should not be one-size-fits-all. Best way to ensure an assignment is to thoroughly know the publication, and that takes time and work.

Good luck.