If you have never ever been camping before then I'd plan to go for ONE night, somewhere reasonably close to home.
Practice putting the tent up in the back garden before you go.
Take extra blankets / fleeces to sleep in, it gets cold at night even if the weather is good and there is nothing worse than being too cold to sleep!
Minimise the cooking / cooling gubbins. Take sandwiches for lunch. Disposable BBQ, packet of sausages in an insulated bag with frozen bottles of water & milk. Apples, nanas, biscuits etc for snacks. Croissants or cake for breakfast. Or even a chippy dinner 
If you enjoy yourselves you can then start building up to the full coolbox / stoves / plates etc but tbh that is the most complicated bit IMO!
I now do things like make and freeze bolognese to heat up, with fresh pasta that means you're not crouched over a gas stove for ages.
I also have a picnic hamper with a full set of plates, knives, forks, bowls, tin opener, pans, teapot, kettle etc all packed in it - so we just have to pick that up rather than remember to pack a massive long list every time. I've collected all the bits over the years but it would be a big outlay all at once - not worth doing unless you fall in love with life under canvas!
Loads of spare plastic bags. Always useful for rubbish, wet clothes etc.
Good luck!