Hi Michelle,

do I understand you right that you want to allow people to read documents in a library but not modify them. However they should be able to create / upload new documents, but after adding again they only can read the document?

If that's what you want to achieve you need neither Workflow nor Forms. Instead you would need to go to Site Settings and afterwards Site Permissions to add a new Permission Level

In this permission level you can create a new one (maybe based on Contribution Permission Level) and remove the "edit items" permission.

Afterwards in your library you would need to change the permission of your contributers from contribute to your new permission level.

Would that be helpful for you?

Kind regards

Enrico