1994 Marquis Air suspension & oil type

I just bought a 94 Marquis with only 55K miles on it the other day. It is in great shape (older person had the car since new) and I have two questions.
1 - The auto store said it requires synthetic oil only. I put it in, but I have no way of knowing if synthetic was always used for the first 55K miles. Does this really need synthetic oil?

2 - When I start it up (or turn the key) I hear a pump running under the hood and I realized it has air suspension. Is it normal for it to "pump" itself up like that on start up? The car runs great and it is like new inside so I know it has been taken care of.

Thanks,