You can find you Chase referral link by going to https://www.chase.com/referafriend/catch-all. There’s a limit of 50,000 points/$500 which can be earned each year via referrals. Reward amount per referral varies; current offer on the Freedom card is $100/10,000, for example.
At the bottom of the above referral page, you’ll see a meter which tracks how many referrals you’ve done for the year. Useful for keeping track of how many referrals you’ve accumulated and how much you have left. It’s possible everyone already knew this, but I just learned about it a few weeks ago from Reddit user garettg.
The 50,000/$500 limit resets based on the calendar year; if someone signs up with your link on December 31st that would count toward the prior year and if they sign up on January 1st that would count toward the new year. (See also this interesting article from Nick on Frequentmiler regarding how to time your Southwest referrals right to maximize earnings toward a Companion Pass.)