How would I change the angular unit of a layer?
For some background, I have created an Excel CSV table with x/y coordinates in decimal degrees and would like to use to the "Make XY Event Layer" tool on that table to get a point feature layer (if that is how it works), but the units are set to degrees and I don't know how to change that.
Longitude and latitude have the units degrees.
If you want them in some other coordinate system, you have to Project the data to a new coordinate system appropriate for your area
Would you enter the x/y coordinates using the degree symbols in the excel table?
No definitely not.
Your coordinates need to be in decimal degrees in a numeric field.
You would be advised to fix up your data first before you try to map it, or this will just be the start of your problems
Convert Coordinate Notation—Data Management toolbox | ArcGIS Desktop