4 weeks to lose it

[Guttle]

A familiar story- event coming up, I want to lose about 3kg (half a stone?) to fit in a dress.

I can get it on but it‘s just that bit too tight.

Party is in 4 weeks.

Starting BMI is 22.5 so a healthy weight, which I know will make it harder.

I‘m going to cut out alcohol for sure. Anything else?

Record all the calories you eat. Work out your TDEE and that will give you an idea of a calorie goal to stick to to lose weight.

Following, in a similar position except my BMI is higher but still (only just) in healthy range. Ideally I'd like to lose a stone but initially half a stone is a good target.
I've always maintained a healthy weight I felt comfortable at, not stick thin but ok,but since having my 2nd child I've put a bit on & I can feel it's unhealthy and uncomfortable.
Planning to cut all food in between meals & alcohol
Never done calorie counting in my life & not familiar with TDEE so a lot to learn!