Did you use the project manager or the editor to install the new SDK?
It is not copied to your project by default since it is still under heavy development.
Use the “Project > Import Lua SDK” menu to do that for your opened project.
After that you should be able to find a new directory named “SDK” in your scripts directory.
It should work then.
The source code for the new API will be copied to the SDK directory, you can view and edit it there. Alternatively you could look in the git repo in “SDK/LuaApi” or on GitHub: https://github.com/Sponk/NeoEditor/tree/development/SDK/LuaApi
About the draw function: No, there is no dedicated draw function. The reason for that is that Neo is multithreaded and Lua is not threadsafe, leading to synchronization problems. This also allows the engine to do some optimizations that would not be possible otherwise.