Some good suggestions for essentials above.
For chilly nights I find a sleeping bag liner adds a bit more warmth.
When I go wild camping I always take a 'treat', something that makes me happy or feel at home. As you will be camping near your car, the possibilities are endless: bring your own duvet, favourite yammies, favourite food, wine, chocolate, a book, music. Whatever floats your boat, makes you feel comfortable and ensures your first solo camp is an enjoyable experience. Then take it from there.
Have fun and I look forward to reading about your adventure
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