How do I find a pubkey and the nbits value to generate a genesis block? I am hoping to create a new cryptocurrency from a Bitcoin fork, mostly for learning, and a little bit of fun. I roughly followed this answer to get as far as I am, but the genesis generator requires a pubkey and an nBits param, and I have no idea how to get these.

Any advice or resources pertaining to those parameters or cryptocurrency creation in general would be great.
The public key doesn't matter, no coins are created in the genesis block. 

nBits decides the blocks difficulty, affecting how long it will take to mine. You also have to modify your daemons code to allow this difficulty.