I was given a 90 honda civic, but no keys. If I pop the door lock out and have a locksmith make a key, will it also work for starting the ignition or are there 2 keys? (one for door, the other for ignition?)

Same.

Not to disagree with TX, but you have to assume that the locks on the doors were not changed at some point, while the ignition wasn't

It is not common, but certainly does happen from time to time