I need an excel expert

I'm moving my website from Weebly to Shopify. I've exported my data from Weebly into a CSV excel file and done the same with my shopify site. Both worksheets contain similar data but I need one single sheet with all the data without getting any of it mixed up or losing any of it. The files contain product listing information on each row. The common denominator is the SKU for each product so I need to make sure that all the data for each SKU is captured on the new worksheet and that it is in the format accepted by shopify for an import.