You'll need to contact your scheduler and/or system administrator for their preference as to how they wish to run your organization. There are multiple ways that games can be input into the system by coaches and Athletic Directors, but you'll want to check with the administrator of your system to determine how they wish to have the games input into the system.
In order for coaches and ADs to be allowed to add games, you would need to enable this functionality in your System Settings. You will need to turn ON Feature #23 to enable this. Once enabled, they may then use the Add Games option at the top of their Game Schedule page. Coaches and ADs are not permitted to import games via a spreadsheet (CSV) as that is restricted only to officiating schedulers.