Create a training list of everything your people need to be proficient in.
This might be part of an induction process that you may have let lapse or it maybe new. Either way, make a list and vary it for front and back of the house.
Place a list on each person’s personal file and ask them to date and sign it when they have undertaken the necessary training. This could be their own shared file in Google docs or a shared page in your staff management software.
Ask them to self manage that list with regular reminders and confirm when complete. This is a great time to get this done.
Set up your training tools and processes in a single place that everyone can manage, there are excellent tools available for this that are reasonable.
Look up the NZ Government website for some basic resources that are available free to get you started.