Hi Maria
I'm at Manchester the same day as you and apart from my bc friends, I have a lot of friends there that will be showing their rottis. One will be in Junior bitch with you I think if that's what you've entered. Personally I would cage the dogs on the bench. Rottis can be a noisy bunch and all my friends cage on the bench. It's a personal choice but I always feel happier having mine in a cage. You never know what you are benched next two so I feel that my dogs are calmer in a cage. Take a towel to cover the front if needed. It helps calms the dogs sometimes.
I would get there as early as you can, then it will give you time to get you and your dogs settled. When you get to your bench (your bench number is your exhibitor no.) there will be two cards on the back of the bench. One of these you use in the ring. From then on it's straight forward. You are usually benched near your ring. Rottis are normally a high entry so with your bitches you probably won't be in until late morning lunchtime. My friends dog who is around 15 months has had an average of 18 in her class all last year.
When you go in the ring, don't go first. Have a few dogs ahead of you. Rottis seemed to be moved a lot. So watch the other dogs in front of you as to what the judge is getting them to do. Also make a note when you go in of which dog is last so you ready to stand yours when the time comes. Sometimes the steward comes round and tells you but not always. Also with a class the judge normally might make a cut and keep anything from 5 upwards in the ring. Just be aware if this happens as it's something that doesn't happen a lot at opens.
In terms of what to wear. I would wear trousers personally. The halls can be cold for one thing. Anything other than black or dark colours would be ideal as you don't want to interfere with the outline of the dog when your running. I just think be smart. You've spent the money and time on your dog to go to the show, so complement your dog.
Have a good time. Let me know what your dogs are called. After i've been in with mine I always come over to the rotti ring to support my friends. It would be nice to see you.
Good luck