Default affiliate link
Settings > System setting > Affiliate link & coupon
Typically, when an affiliate signs up and gets activated, they will have an auto-generated affiliate link that leads to your store homepage. They can find it right from their affiliate account's Dashboard:
But if you want the affiliate links to direct to another page of your store rather than the homepage, you can change the Default affiliate link in Settings > Affiliate link & coupon.
Besides, affiliates can also generate affiliate links for specific pages on your store by clicking Get product link: