Sprint Demos how to Plan and Track?

A Scrum Master is not there to control or track work. What he or she would do is to ensure that Scrum is being implemented well by a self-managing team, including having reviews so the Product Backlog is updated. There may or may not be a demo at all.

In the Scrum framework, there is no such thing as a "Sprint Demo" or "Demo". There is a Sprint Review, which is the next to last event in the Sprint and occurs on a regular cadence. This is the opportunity for key stakeholders to inspect the work that the Scrum Team did over the course of the Sprint and adapt the Product Goal and Product Backlog to maximize value.

Although a demo may be a part of a Sprint Review, it doesn't have to be. For example, for software teams practicing continuous deployment, the work that they did in the Sprint may have already been deployed to the production environment and used by stakeholders. There may be no need to demonstrate work that is already being used.

If it's valuable, you don't need to wait for the Sprint Review to get feedback from stakeholders on the work. Getting earlier feedback is often better. Exactly when or how this is done depends on your exact situation. However, even demonstrating and getting feedback closer to work being done doesn't eliminate the need for a Sprint Review.

How can i better plan and Track Demonstrations so they are not at the end, and if they are at the end i can somehow track it so i know its booked for a certain date or not  

I suggest you don't do any of this and instead focus on the Sprint Review that is described in the Scrum Guide.  The Scrum Master that you have observed is not doing the role of Scrum Master.  Based on some of the questions you have posted, it might be a good idea for you to read the Scrum Guide. (https://www.scrumguides.org) There seems to be a lot of misunderstanding of the Scrum framework in your organization.  As a new Scrum Master, you might be able to help change that.