I don't think there is a hard and fast rule but the more content the higher your SEO the more traffic which in turn generates sales.

There is no written rule for this. If you do not have a lot of content this means not much traffic. So even if you get affiliate link from Amazon and do not make sales in 6 months they will cancel it. So better have 'enough traffic'. Jovo

Hello Sizmob!
The amount of content of your website does not matter right now. It will not be an obstacle - just go ahead and join us. The WA community will be delighted to have you on board. Just go ahead and sign and try it for the first month - nothing to loose. You will soon learn that what you see from the outside is nothing. Come in and experience it for yourself. You'll be amazed.

I think you just need a website in place in order to join some affiliate programs.

But to make money online, you need to create as much content that is needed to get the traffic and the income you want.

Neil