Welcome to SW!!
The meeting is easy, you'll go in, have a new member talk with the consultant & other new members. Then you'll pay & get weighed (only the person who writes it in your book knows your weight), then you'll go and find a chair in the group for the Image Therapy section of the meeting. This talk can involve any number of things, but it generally focuses on how everyone's getting on, if anyone's struggled, new recipe ideas, spreading the word about new products, any upcoming promotions and generally motivating everyone to keep going.
My top tips for the plan would be to focus on the free food and base your meals around that rather than syns or Healthy Extras. Then you have more syns left for fun stuff.
I'd also recommend stocking the house with loads of free foods, so if you feel peckish you can eat loads guilt free!
It also pays dividends to spend time reading through all the booklets you get and working out what you're more likely to eat. Saves so much time in the long run if you spend a bit of time at the beginning understanding it.
Good luck!