performance

iPad pro 5th gen- srry hope i don't sound repetitive I can't seem to figure this out So ordered iPad pro 12.9 inch 512 GB which I thought would be 8 core cpu and 16 core gpu But I've gotten mixed info read where u have to get 1 TB storage to get the 16 core gpu so confused I am even on apple sight it's not in ur face explained and to top it all off am very new to apple products windows no more but stupid i am do i even need 16 or would 8 b alright and does it come on the 512 hope understand ? at work ina rush srry kina flighty too ha lol thx in advance