Transfer all data from one iPhone to another

When I set up my new iPhone, I accidentally hit that I didn’t want to transfer the data from my iCloud to my new phone during the set up. Now that my phone is set up and the SIM card is in my new phone, how do I transfer all the data that was on my old phone onto my new one using iCloud? Everything I’ve looked up only gives instructions on how to do it if you’re just setting up the phone. I backed up my old phone so everything is already on my I could, I just don’t know how to get it on the new phone.