One of the first rules of being a good sub is silence. Your Mistress doesn’t want to hear your opinion. You need to start practicing speaking less. If you never had experience with dom/sub relationships, you might want to start slow.
Naturally, you shouldn’t do anything that you don’t want to do. Subs are not doormats, and not a single dominant would desire that. Dominants wish for someone who truly wants to be owned.
Some people enjoy the feeling of helplessness and lack of control. They love passing the baton and letting someone else do all the work while they just serve. But you should know that doms have a huge responsibility on their own. It is not easy to be a dom, and your job is to make it possible and enjoyable for both.
More importantly, when we say listen, we mean everything and not just what the dom says. You should also observe the body language and everything your dom does. Everyone loves different things, and everyone is unique. Some doms enjoy bratty subs that just beg for punishment, while others require unquestioned worship. You will need to listen to your partner so both of you can enjoy the relationship.
Furthermore, you must retain from asking questions while in the role. You are not the one that should talk about what they think or what they should do. There is a person in charge, and yours is to obey.