Just adding up to @Rohan_Raj , here are some links for you:
If you don’t know anything about ML, there are many good courses to do,  a good free one is the crash course: Machine Learning Crash Course  |  Google Developers 8
If you know the basics of ML, then this tutorials is a very good start for TensorFlow:
  
      

      TensorFlow
  

  
    

TensorFlow 2 quickstart for beginners  |  TensorFlow Core 5



  

  
    
    
  

  


After you feel comfortable with the API, this tutorial for transfer learning will give you the idea of how TL works: Transfer learning and fine-tuning  |  TensorFlow Core 1
Finally, for a Transfer Learning for Plant disease, detected from pictures of the leaves, this tutorial can get you cover: CropNet: Cassava Disease Detection  |  TensorFlow Hub 1
hope this helps