Hello friends. i need little help in apointment booking system.

You are going to need a large number of tables, it's not practical to detail what the structure should be here.

First up, have a look at the systems that already exist and either go through them and their databases so that you understand what they've done and why. If you can't get access because the system is proprietary you should be able to still see some screen shots or maybe a demo which will give you an idea of the type of data being collected.

Then you need to look at what you want your system to do. What can you leave out? What needs to be added in?
Are you going to use a base system like WordPress or Joomla to handle user management or do you need to build in all that security/user stuff?

Once you've got your business plan drawn up you'll have a better idea about data collection and competitors etc.