Giving notice confusion!

Please someone help my brain is fried!


I am English, my partner is northern Irish. We live in Northern Ireland but want to get married in England near where I am from. We are so confused about giving notice. Do we need to give notice over here Aswell as in England or just England? Also we have been told we have to fulfil a 7 days residency before the wedding. How do you prove this and what does this mean?
We are just about to book our wedding but we are stalling as we don’t want this to be a balls up.
If someone who’s been in this position could clarify that would be great.
Thanks