Filemaker has a number of tools that make it fairly easy to import data from an Excel file.
It could be as simple as dragging the excel file onto the Filemaker application icon or shortcut. (That creates a brand new filemaker file and imports the excel data.)
It can also be a much more complex process depending on your data and the structure/function of your database.
Check out the Import Records tool in the file menu. It can be used to import records from an excel file and has a number of options that control the result you get.