You seem confused between what an INFORMAT does and what a FORMAT does. An INFORMAT is instructions for how to convert text into the value that is stored. A FORMAT is instructions for how to convert the value that is stored into text.
If you have a date variable and you want to print the value in MDY order then use the MMDDYY format.
PROC PRINT DATA = music;
FORMAT ReleaseDate MMDDYY10. ;
RUN;
Of course if you want your friends in the UK to understand it then it might be better to use the YYMMDD format instead as nobody will confuse the value 2018-12-10 as meaning the twelfth of November instead of the tenth of December.
Did you try using the ANYDTDTE. informat to read your existing CSV file?
data test;
infile cards dsd truncover firstobs=2 ;
input Album :$50. Artist :$50. ReleaseDate :ANYDTDTE.
TotalCertifiedCopies ClaimedSales Genre :$50.
;
format ReleaseDate yymmdd10.;
cards4;
Album,Artist,ReleaseDate,TotalCertifiedCopies,ClaimedSales,Genre
Thriller,Michael Jackson,"November 30, 1982",46.3,65,Pop
Back in Black,AC/DC,"July 25, 1980",26.1,50,Rock
The Dark Side of the Moon,Pink Floyd,"March 1, 1973",24.2,45,Rock
;;;;
proc print;
run;
Total
Release Certified Claimed
Obs Album Artist Date Copies Sales Genre
1 Thriller Michael Jackson 1982-11-30 46.3 65 Pop
2 Back in Black AC/DC 1980-07-25 26.1 50 Rock
3 The Dark Side of the Moon Pink Floyd 1973-03-01 24.2 45 Rock
... View more