Don't be scared, it's really friendly and everybody is there for the same reason. Remember even the consultant and the target members have been where you are and know how you're feeling.
You will be welcomed by the consultant and taken over to a table to fill in a registration form. Whilst the other members of the group get weighed you and any other new members will receive a new member talk where you will have the plan explained to you. This takes about 30 mins. Image therapy then happens where you all sit in a horseshoe and the consultant goes over any new news. My consultant then goes around the group discussing individuals loss/gain and how their week has gone. This is when other members can also give ideas if you're struggling or you can share any new recipes with the group. Once everybody has had a turn my consultant does the raffle.
Good luck on your journey. Slimming world has changed my life and has allowed me to diet, eating the same as my family and my daughters never seeing me starve myself to lose weight.