So this year I won't have a textbook but instead have been told I can just do anything with my classes. The reason for this is that the homeroom teachers don't like that me (5TH and 6TH grade) and the Korean English teacher (3rd and 4TH grade) are "doing their job" . So they will teach the textbook while I'm expected to do something.
Can anyone give some advice as how to use these classes meaningfully?
I used to be terrified of being put in this situation. But last year I literally never opened the book in my 5th and 6th grade classes. I taught those with their homeroom teachers, (who were seriously great at helping me translate things and explaining some activities) so it could be difficult on your own. What I did was use a short review presentation at the beginning of each lesson covering what they have been learning in their books with their homeroom teachers. Then I would just do one or two major activities or games depending on the length of the activities or games.
I ended up really enjoying that method of teaching, (as did my students) and I think I only ever once used a "bomb" game. Even with different themes, they tend to get old, fast. There is a lot of material out there if you know where to look. I would find out what books their homeroom teachers are using and search for various activities from that. I typically did 4 classes (2 classes per week) per chapter: 2 listening and speaking lessons and 2 reading and writing lessons. Of course this can be modified to fit your students particular needs. In my case they also had 1 lesson per week with only their homeroom teacher.
Of course if you'd prefer, you can do whatever the hell you want, since you have been given that freedom. I was told to stick to the lesson timeline in the book, but to not use the book much if possible.