You just need to bring your best attitude.
You certainly don’t need to go through your fridge and cupboard to throw out all the unhealthy stuff. Or tell your friends that you can’t go out to eat/drink for 8 or 12 weeks.
Throughout the programs and especially in the first week, you do not need to make any significant changes. We will focus on small changes over time, rather than huge changes overnight as this is far more sustainable.