How can I run workshops with new guests everytime?

Hi,

How can I run workshops with new guests everytime. I don't need to create a team.

I run workshops at my company for external clients and with every workshop comes new guests.

Is there a way to invite guests to a one time workshop, and what would be the best plan to do so? 

The maximum number let's say every time for a workshop is between 30 and 40.

Best,

Bassam