@mcbeth99, if there's a common field between the attributes spreadsheet and the shapefile that would facilitate a link to pull in all of your populated fields and attach them to the features in the shapefile, you could use the Join Field tool (found under ArcToolbox --> Data Management --> Joins --> Join Field).
If your workspace is a geodatabase, you could also use the Table to Geodatabase (multiple) tool (found in ArcToolbox --> Conversion Tools --> To Geodatabase) to bring in a bunch of tables at a time for joining (again, if there's a unique-ID field common between the features and attributes) to your shapefile or feature class.
Kindest Regards,
t