You need their feedback for you to improve. If your speech is about some physical task to perform e.
How to organize an event at your college. A demonstration speech is a "how to" speechin which the speaker demonstrates to the audience how to do a particular process or activity.
However, if your audience is professional cooks, such topics would look very basic and irrelevant to them. Good demonstration speech ideas How to build a good website. If you can, get audience members doing it.
This allows the audience to seek clarification on any of the steps which were unclear. Learn to code from the comfort of your home.