We have quite lots of answers in this forum:
Image fusion
- Image Fusion Using Sentinel 1 and Sentinel 2
- Sentinel-1 fusion problem with Landsat 8
- How to do georegistration and fusion images
- Optical image fusion
- Image fusion
Agricultural applications and image classification
- Crop monitoring and yield mapping with sentinel 1
- Classification of GRD product
- Sentinel-1 Intensity analysis
- Agriculture for S-1 GRD
- Graph Builder
- Supervised and unsupervised classification, Sentinel 2
- Correlation between NDVI and SAR parameter
Try to get from these sources what is best for your study. Don’t just follow recipes, try to understand what is done and why.
If you are new to SAR analyses, there is a great online course on all kinds of radar applications:
https://eo-college.org/courses/echoes-in-space/
New tutorial (February 2020)
Synergetic use of S1 (SAR) and S2 (optical) data and use of analysis tools