The simulation drawing tool panel contains all the tools you need to draw the structure of your simulation.
Click on a simulation object from the panel, then click on the simulation window where you want it to be created.
Simul8 will automatically connect objects together where it thinks it can predict what you'd want to happen but you can change the routing arrows using the connection tools. You can choose to display or hide the routing arrows using the Show Routing Arrows button on the Quick Access Tools.
The Basic Building Blocks tab contains the core simulation objects you'll need to build your simulation. The additional tabs show more advanced objects that you might need in some simulations.
You can also create your own custom objects and group them in your own tabs.