Hello.
Magento has strict requirements to the format of CSV file, specific columns, names of headers etc. Most likely you will have to adjust your file for it to fit for upload via System-> Import/Export.
Here is the article with the list of required for import columns, it might be useful for you -
https://www.mag-manager.com/useful-articles/tipstricks/required-csv-file-values-for-error-free-magen...