Custom fields

[Arti Pathare]

How do I get the details of custom fields that have been created for classic and next-gen projects so, created date or created by? 

I am using Jira Cloud.

[Nic Brough -Adaptavist-]

The date that a custom field is entered is not recorded, as it's not useful information (you only really care when data is entered into it)

The "details" of custom fields can be seen (and edited) on Admin -> Issues -> Custom fields.

[Arti Pathare]

Unfortunately, I do need that level of information as it will be useful to know who has created the field and when.

Is there a link to a list of custom fields that are available in the Jira Service Desk Cloud OOTB?

Thanks

[Nic Brough -Adaptavist-]

Whether you think you need that information or not is irrelevant really.  It is not recorded and hence it is not available.

I'm not sure what you think "a list of available custom fields" would be or how it might be useful.  By definition, a custom field is a field that you choose to add as a customisation.  A list of "available" fields would be long and probably useless as it would be a list of every possible name of a field repeated for each type of field you can define.