Why do you want a job? You clearly don't need the money considering your lottery win so why not volunteer or something instead.

Break out the suit and tie.

Good news maybe you can buy your dog back.
No, that is neither an interview, nor an 'interview' it's a recruitment day.

On the day: Suit up, make eye-contact, have good posture, remember your manners, give firm handshakes, get alone with people.
Before: Research the company as best you can. Practice 'obvious' questions such as why you want the job e.g. to develop certain skillsets, etc.
You're not only going to be assessed on how you behave/perform, but also how well you interact with others. Just use your common sense, try to look professional and not someone who's just rocked up off the street.
Does Aldi even exist?
Nah, good luck.
You know 'the farm' is just what they tell kids right?