Hi Bhawan,
If your Page Type is Document, then you should be able to use a subform page for lines like you do in NAV.
And yes, to use the NAV Development Environment, you can create and use the Sandbox Container environment. It can be on Azure, or on-prem on your machine with Docker.
Here, you will have access to the C/SIDE Development environment, but keep in mind, that you still have to follow these guidelines:
* Make sure you are not modifying any base objects
* Use Events and Extensions to extend base objects if needed
* Follow the Object Range rules (if making a custom table, even the field IDs have to be in the object range; cannot have field ID 1, 2, etc., unless Microsoft has issued you a reserved object range for AppSource, or you have an ISV object range)
* After you make your solution, you will need to export all new objects as .TXT in new format, get deltas (there is a script for it), and then use the Txt2AL scripts to convert them to AL, and then use Visual Studio to debug/compile and get your .app
You can find all of these rules in the Mirosoft Docs for AL under the Business Central docs:
docs.microsoft.com/.../devenv-dev-overview
I hope this helps. If my response has answered your question, please verify by clicking Yes next to "Did this answer your question?"