It is not possible to load anything "without opening AutoCAD". But I guess what you means is that because your plugin is automatically loaded as "auto-load" plugin package, you also want to auto-load custom ribbon menu item that is designed to run your custom commands.
Noticed that I used the words of "that is designed to..."? that means you need to create the custom ribbon menu item(s) by yourself. The most common way to do it, is to create a partial CUIX for your plugin, and then simply included in the plugin's auto-load package, off you go.
In rare cases where the business requirements may warrants, you can dynamically generate ribbon items with code by your plugin itself, but it might be beyond your current consideration.