Can i trade in a completely paid for i phone 4 for an i phone 11 or higher

An iPhone 4 has no value so Apple will not give you credit to a new phone. You can recycle it at an Apple Store.

The iPhone 4 has no value. It was discontinued 10 years ago and is no longer usable as a phone at all in most of the world.

The iPhone 11 was discontinued over a year ago.