How to Change Clothes & Shoes
To change clothes and shoes for your MyPlayer character in NBA 2K21, open the options menu when you’re in the Neighborhood and open the MyPlayer player option.
From there, go to the Clothes section to change clothes, shoes, caps, and other accessories.
As for changing in-game accessories for NBA matches in MyCareer can only be done inside the locker room.
NBA 2K21 – All Locker / VC Codes