Help Is cocaine effective enough to od?

[B4mbi]

I finally brought up the courage to reach out to an old friend who I met while I lived at a care home. I know they do drugs, and they said they could hook me up with some cocaine. I feel so lucky they responded to me but is this a good plan? I've never taken any kind of drug in my life before. I want to lie and say I need enough for two people because I want to share it with my friend, but I realise that could mean anything.

How much cocaine would I need? And should I mix it with alcohol? Is this a good idea? Everything else has failed.