If you wish to give a particular individual more Passes to distribute and put them in charge, you need to convert them to a group.
If you are an event admin, you will find this option on the drop down choices next to an individual. Just click on "Convert to group'
If the option is not there, it is one of 2 things:
You may already be inside a group. You can't create a group within a group
You may be an Area Manager and need to add the correct permission (see below)
I want Area Managers to be able to convert individuals to groups
In Event settings, to to Event permissions and find the Assign Groups row. Make sure this is ticked for Area Managers: