Is there a way to use my mouse or trackpad with my iPhone
While you can pair a bluetooth keyboard with an iOS device and use it, Apple does not support for pairing a bluetooth mouse or trackpad.

I did find that there is a third-party app for use on jailbroken iOS devices that allow you to do what you want. It provides an alternative Bluetooth Stack which provides the ability to use the trackpad or mouse. See here for more info.