How much equity and royalty percentage to ask for?

I have been presented with a massive opportunity, to become the foundation of a new startup's marketing department, responsible for building and managing their website, funnels, email campaigns.The startup is in the supplement space, founded by a professional athlete who has a massive network with other athletes, and a contract with a laboratory that creates the formulas. As legit as it can be.As we know each other well, we have agreed on closing a contract where I am given equity and commissions from all sales made with any of the campaigns (as long as they are active).HOW THE F* I DECIDE HOW MUCH EQUITY AND COMMISSIONS I SHOULD GET?I literary have no idea. I guess equity would be low (5-10%?) as the commissions are where I get my money from. The online store, multiple funnels, email campaigns, to me it feels more than fair to get paid mostly from the performance of those only. But still, how are equity and royalties decided on?Thank you! see hubwealthy.com/wealthy