Any tips on doing due diligence on a vacant raw land in Oakland?

[Vicky Gu]

How are you all doing?  Any land experts here?   Can I get some help on how to perform a due diligence on a vacant parcel? Some basic facts about this land:

- located in Oakland CA

- it was subdivided in 1991

- there are homes on each side of the parcel

- the land is unentitled (I don't even know what this means haha, I'm a newbie to land)

- I called utilities, there is water meter already, gas and electricity need to be installed

- the land is on a hill, then flat on top for future house

Any input will be helpful, I have 10 days to do due diligence before I can back out of the contract. Please help!

Thank you!!