Please have a look at these posts and topics:
- Webinar | InSAR for land subsidence using Sentinel-1 and SNAP
- Subsidence map in 3d view
- DInSAR result scale
Please also note that differential SAR interferometry is something complex which cannot be fully understood within one week. Especially when it comes to errors and where they come from you need a proper understanding of what is done in the single steps and why.