No, it won't slow your site because it is not using the resources of your server rather it's using the Zoom platform to render the meeting window. The load on your server will be similar to a normal page visit.
Having a decade-long experience with web development, there came a major turning point in my life that shifted all my attention towards progressive education models. I took a special interest in creating eLearning tools. Now, I express my ideas through the “language of code”: LearnDash Student Voice, Adaptive Learning with LearnDash, Virtual Classroom for WordPress and Zoom WordPress Plugin are some of my plugins. I help educators, coaches, teachers, and field experts combine technology with education to make it scalable, flexible, accessible to the masses & at par with 21st-century learning methodology.