Noob help... almost got it(instore)

[gustavo.fring]

I’ve been studying carding for 2 months now, last weekend me and my homie tried it out, we both bought a 101 dumP from golden dumps (Crédit) . Mine workers but his didn’t and we don’t know why. My question is what’s the right/best way to find working bins ? I read somewhere that we should buy in bulk and just try them out at small shoPs or use the paid parking machine just to see if they work , will that work or is there another way ? If so, where the best place to get dumPs in bulk ? Any help is appreciated!