Here is one path to follow. There are many other ways.
1) choose image sensor
2) study output data formats and control methods for sensor
3) choose appropriate microcontroller for simplest interface to image sensor
4) choose output data format for delivery over USB
5) choose a USB controller for easiest interface to your microcontroller
6) prepare schematic diagram with sensor, uP and USB controller plus the necessary clocks, reset controller, power supply, debug and other accessory functions
7) layout circuit board
8) fabricate circuit board
9) assemble circuit board
10) write software to run on microprocessor to collect data from sensor, change its format and deliver it to USB
11) test and correct software until working
You may get the sense that this is not a simple project. I am concerned that it is perhaps too difficult for you to complete.