I know exactly what you're talking about, I had a large project to do over a year ago and I had to learn ADO.NET and it was so painful because there is hardly much out there about ado.net. You might want to think about getting a book btw, David Sceppa's programming ADO.NET core reference is pretty good.
ok, a DataSet an in memory representation of your tables or schema, a dataset contains Tables, so when you have the table you want, you do exactly what you mentioned.
(ds = dataset)
DataTable dt = ds.Tables;
DataRow row = dt.NewRow()
Now you can do what you want with 'row'
Remember to persist the changes with
ds.AcceptChanges() //if i'm not mistaken!?
Yes, i didn't forget, You probably don't see the NewRow() on intellisense because 1. You don't have using System.Data on the top, and/or 2. You don't have System.Data.dll referenced.
I Hope that was helpful