Naturalisation Question & MN1 Question

I came to the UK with my wife and a child on 15 February 2014. Child was born outside the UK in 2010. Myself and the child were dependents. My wife was granted indefinite leave to remain (ILR) on 21 January 2019. I was granted indefinite leave to remain (ILR) on 1 April 2019. My son did not apply for ILR because his Visa was still valid till 15 February 2020. Now we are in the process of applying Citizenship, and I have the following questions:

(1). Can I apply for Citizenship together with my wife when she applies or I have to wait for 12 months after getting ILR to apply or wait till my wife gets her citizenship?
(2). Does our son need to apply for ILR or we can straight away complete the MN1 form for him?

1. You need to wait 12 months on ilr. The only time you don't have to wait is if you are married to a British citizenship, which you are not.

2. Yes, he needs ilr an you are running out of time if his visa expires next week. You should have included Him in your ilr application last year.