Hi,
You can open an Excel spreadsheet in Microsoft Project to launch the Import Wizard. You will need to map your Excel fields into the Project fields. As Skip notes, there are multiple date fields including Start1 through Start10, Finish1 through Finish10, and Date1 through Date10.
As a start, create a quick project in Project add the fields you need to the Entry table. Save As an Excel file and look at the exported data in Excel. That will give you good guidance on how the Excel file should be structured.
Post back with more question as you need.
I hope this helps.
Julie