Hi Shayla,
Just to make sure I get what you're trying to do here, you want to populate the Class field with data from the Customer Type field?
Class is part of the Estimate table, whereas Customer Type is part of the Customer table, so populating values from one with the other would require a fair bit of in-depth customization if it's even possible.
If you just want to have the Customer Type field on the Estimate, you could add a Linked Field from the Customer table to the Estimate table.
- Justin