Hi
I think the caravan club have a list on their web site of equipment needed. We printed it off some time ago out of interest, we have to say we don't carry everything on the list, we have 3 kids, now aged 9, 10, 11 and have caravanned for the past 7 years, I also did it as a child.
If you buy your caravan from a dealer, you may get what i think is called a starter pack, worth checking what it consists of, could consist of an aqua roll for fresh water and waste water container. I think that's what my sister had when she bought her van earlier this year. You may also get a card which gives you a discount on things you buy from their shop.
To budget, its also worth looking on web sites, eg when we up upgrade our van last year we needed a new awning, it was cheaper to buy on line. Numerous companies have been mentioned on this forum in the past.
Don't forget to budget for Caravan insurance and storage if you can't store the caravan at home. Membership of caravan club and or camping and caravan club. You will find various comments to both on this forum
Some ideas to get you started from our experience:
Towing mirrors - forum members have made recommendations in the past
Spare wheel for caravan.
Aqua roll for fresh water and tube for filling and pump
Waste water container, recommend both fresh and waste water containers are those with wheels, the kids can always help and like doing this.
gas bottles and spanner.
battery for caravan, may be included
electric hook up cable, some hook up cables are shorter than others, we have ended up buying a longer cable on site in the past.
caravan step
crockery eg plates etc we have melamine but carry glass wine glasses and proper mugs. Tea, coffee and red wine doesn't taste the same in melamine, our opinion
cooking utensils, you can use the same as you do at home
kettle
pots and pans
torch
first aid kit
children's paracetamol or other pain killer, you never know when you need it
Awning and breathable awning carpet, pegs and mallet.
table and chairs for sitting outside for adults and kids. We have a folding picnic table with 4 seats plus folding chairs for us adults and the kids
BBQ and tools
Sleeping bags or duvets - the choice is yours
Folding crates from DIY shops etc for kids toys
Something i was taught as a child and still practice - think weight and do you need it and will you use it.
Hope this helps. Good luck
Annette