For CPL or CIR a nice Shirt, pants and shoes should do the trick. Blue pants white shirt are probably best, but anything nice and presentable should do.
I wouldn't rush out and buy a uniform. Hunt through your existing clothes.
Remember that your first job may not require the white shirt blue pants anyway.
Also folks remember that IF YOUR EMPLOYER NEEDS YOU TO WEAR A UNIFORM THEY SHOULD PAY FOR IT OR GIVE AN ALLOWANCE!