Welcome!
My first couple of camps, I had airbeds straight onto groundsheet, with sleeping bag on top....freezing cold. So definitely wise to heed all the insulating advice on previous posts!
Main other thing to mention...make sure you've had a practice pitch or two of the tent, to check you've got everything needed and reduce stress when you get there.
And...Once you have gathered your "Stuff" try (If you can) a practice packing of the car....Saves a bit of stress on the day of departure knowing everything will fit...
Folding chairs/tables etc...Pots and pans that stack inside each other,gear that rolls up or folds flat etc etc all help reduce space..Think about items that can have multiple uses(again to save space)
I second the suggestion of (once on site) having a look round at other campers set ups...You will get so many Ideas for future trips doing that...
Welcome to the forum...And enjoy your 1st trip...
Jelboy
------------- Campers of the storm,Into this world are born