To agree on the ground rules of the training, you can start with setting a few ground rules yourself and ask participants to add to the list.
At the start of a training, mutually determining the ground rules with the participants, can help to build up a safe learning environment. At the same time, it can help you as a facilitator, to refer to these rules if discussions seem to go off subject or out of control.
You can ask:
You can have them put their answers on post-its and place them on a flipchart. Go through each rule to make sure they are clear and then agreed to by all the participants. Keep the flipchart with the ground rules visible throughout the training to be able to refer to it when needed.
If you are hosting an online session, here are some rules that RNTC sets out in order to ensure a good training experience for all:

Ensuring camera is on, to ensure engagement and focus is suggested. If connection speeds are bad this can hinder video usage and it is possible to negotiate this with participants. Microphones should be set to mute when not talking.

In the chat function, if participants would like to contribute, they can use the raise hand function.

Avoiding clutter and frivolities helps ensure the chat function is seen as a training space and not a social space.

Inform participants of which devices are needed for the session and which technology will be required ahead of the session. This allows participants to ensure they have the correct devices to ensure seamless learning.

Under the Chatham house rule, anyone who comes to a meeting is free to use information from the discussion but is not allowed to reveal who made any comment. It is designed to increase openness of discussion.

Establish the break schedule and when lunches and other meals will be observed. Surface if there are any special considerations.

Establish if screenshots are appropriate and don’t pose a risk to individuals in the group before taking photographs or screen grabs.

Sessions should be recorded for participants who may drop out of the call during the training. The recorded sessions are placed in the drive for a period of 24 – 48 hours to allow participants to catch up missed sessions. The intention of these is not to have a library of sessions but rather to provide revision or catch up material. Recording a session needs to have the consensus of the group.
As a facilitator, you want to encourage active participation from all the participants and encourage everyone to share experiences and ideas. Here are some tips on how to facilitate this:
Managing group dynamics and energy
Constructively challenging
Use questions to respectfully encourage groups to push themselves and stretch their thinking, for example:
Questioning and active listening
Valuing what people are bringing and what is emerging
Threading/summarising/signposting /recapping