Data Retention Policy Document + Other Documents I may need

Help with some data policy documents for my business.

I cannot disclose much about the business currently but simply put I need any and all policy documents created for my company/data processes that my clients would require to see should we engage in business.

My business workflow:

Client supplies me with digital data (This data is highly valuable business data - Not personal information but business data). ---- I create a digital product for my clients and use the data provided --- I send completed digital product to client and delete all data once project is signed off as completed.

I just need to make sure I am not restricting client business by not having a solid data retention policy/ any other processes in place and require help with this.

If this is something you can help with, I am happy to attach a NDA and speak further.

Regards,
Krish Kachhwaha