There is no "full course" to creating the inventory database. If it was a complete guide to an entire database it would be a seminar or a template. The tech helps are not long enough to cover that large of scope, they are trying to teach a specific function or goal. To give you a new tool to use in your database designing.The tech helps also don't continue on each other unless they're numbered like Eclipse Timer, Eclipse Timer 2, etc...

If you want a "full course" you should start with beginner 1 and work your way up through the training classes. I see you only have beginner1/2 so unless you have previous experience the tech helps are probably over your head at the moment. The training classes would teach you about Access and how to build a full database. Not an inventory database specifically, but will teach you how to do similar things that you could apply to your unique database.

You could review THIS SEMINAR and see if it would cover what you want.