If you ordered a mobile pass, then the confirmation email contains all information you need to activate (although this is not necessary until you're about to board your first train).

As to the other people in your group: 

If they ordered their passes themselves, then they should also receive a confirmation email, but that has no impact on your ability to activate your own pass.

If you ordered their passes for them, you are the only person to receive the confirmation email and you should forward their pass numbers to them.

Sometimes it can just take a bit of time until you get the confirmation mail, but not much longer than a half hour.

Hi @emmaruaro, I noticed that you have a DiscoverEU Pass connected to your email address. Could you tell me if your group members have the same type of Passes?

If yes, and they haven't received the confirmation email, please contact the DiscoverEU customer service team via https://discovereu-wave6.zendesk.com/hc/en-gb/requests/new