To count the rows of csv file we can use Get Files Rows Count Input in etl. How to find the number columns of a csv file?
Just read the first row of the CSV file using Text-File-Input setting header rows to 0. Usually, the first row contains field names. If you read the whole row into a single field, you can use Split-Field-To-Rows to have a single fieldname per row and the number of rows tells you the number of fields. There are other ways, but this one easily prepares for a subsequent metadata injection - if that's what you have in mind.