Do I need to promote the Club to make money?

The way the system works is that you earn on 5 sales from 5 levels down (If you activate all tiers/products) so yes, you would need to start that off by advertising it to get at least one person in.

It is not hard though. Even if you only managed to bring one person in, that person might bring in 5 others who bring in 5 each who then bring in 5 each etc.

You can still end up with a lot of sales just from one referral. The more you bring in the better.