The formal procedure of the GC mock conference can cause a lot of confusion amongst students (and you as well). While there is standard protocol to be followed determined by the GC/Model UN program, the following is a suggestion for how you might simplify the protocol so there aren't so many rules, and the students can more successfully debate and collaborate, ultimately having more fun in the process.
I know as a GC assistant, you receive training about how the mock conference should be done. However, you truly do have the freedom to decide how you want to conduct it. I suggest taking what you learned during the jornadas and adapting the conference to fit the level of English, as well as engagement, to your students.
Class #1
Go over the process of how the Speaker's List (a.k.a. opening speeches) will be done. Do a dress rehearsal, having students yet again practice their opening speech in front the class. Tell the audience to take notes on their classmates' speeches in order to give feedback as well as ask questions about each country's position.
Class #2-3
Go over how the moderated caucus will be done. Here is where I propose the biggest change to the conference structure. The moderated caucus, where students have to formally defend and debate their positions on the spot, proved to be one of the more stagnant, sometimes even painful parts of the mock conference for some of my programa classes. So instead of having this be done impromptu, I suggest taking a class or two to sort of set up a stage for this part of the debate.
One idea for how to do this would be to have students identify which of the other country delegations they would like to work together with based off of what they heard in the practice opening speeches. Then, within these groups (you can call them "blocs" to make it more "UN-esque"), they would spend the class discussing and formulating potential resolutions to their countries' issues. Have them brainstorm ideas and encourage the blocs to go home and do more research to help support these ideas. When it comes to the real mock conference, having these pre-established blocs will give students a crutch to lean on if they're hesitant or unsure of what to be debating.
Class #4
The last class should be spent on the unmoderated caucus and resolution writing processes. Since the students should now be organized into their blocs, explain the unmoderated caucus and encourage students to get up and start to discuss with other blocs. By moving together in bigger groups, this should foster more discussion and ideas for how to collaborate on resolutions.