View Seats: I have ... questions

For my business, I have been requested to accept designs through FIGMA.  I will not be creating the designs, just consuming them.  How do View Seats work (I’m assuming that is what I need)?  Does each client need to provide me with a View Seat for their designs?  Can I get a view seat from the Free plan and use that to access any design?  Do I need to have my own paid plan?

Example Scenario:  Three separate clients want to submit designs to me in FIGMA.  What do I need to do in order to access those designs?

Thanks for any assistance!