iOS provides a lot less ways for third party apps to dig into the OS and interact with other apps. The same thing Android fans hate about it, the lock-in and lack of customizability, offers it a lot of additional privacy protection.
In general though, regardless of your phone ecosystem: Remove as many apps as you can from your device. Only install the ones you need and remove ones you don't frequently.
More or less the same as a stock Android device has, the difference is that it keeps on sending data to Apple instead of Google. If you trust Apple at their word about being good stewards of your data you might think this is OK. If you see Apple as the corporate entity it is and you have a healthy distrust of any and all such entities when it comes to them keeping their word when money comes into play you probably want to limit exposure as much as possible.