It appears I might be heading into renting fairly big warehouse at 30k$ a year lease can not find any cheaper one as they are snatched right away. So I still decided to go for it because almost half of my GPUs are sitting and collecting dust at home unable to use. Now agent said it is my responsibillity to bring your own electrician to test electrical output, but with EE degree I thought to do myself (bit apprehensive about bringing outsider because wanna keep mining operation and location under a sleeve due to high cost of equipment being used) but I was wondering what I can will be appropriate. Will it be a simple job and what do they test?
My EE degree is 15 years old and I am all software now but still remember basic electrical stuff like P=IV, V=IR and stuff like that.

Should be able to determine the setup based on fusing if accessible. No reason aside from certification that you couldnt do it yourself. In my state you can wire up your own domicile without certification as long as it passes code.
Those laws are basically all you would need. And the codebook for proper wiring laws. Its easy peasy, at least for home wiring, but shouldnt differ for commercial really.