Think of a good name for your new package and then navigate to OptimizeMember >> General Options >> Define Membership Levels and Packages. From there, scroll down to the bottom of the panel until you find the "Add New Package:" under the "Packages".
Type in your preferred package name and then save your work by clicking the "Save All Changes" button at the bottom of your page.
Once done, you should be able to view the list of defined packages when you go to a certain post/page, under the OptimizeMember option setting and assigned package/s on that specific post/page.
When defining a package name, please take note of the following:
1. Package names do not go well with non-alphanumeric characters
2. It should be in lowercase.
3. Use package names without "_", "-" or spaces. Just numbers and letters in lowercase.