You can search online for journals in the field of education. In fact, you could also narrow down your search and use keywords like "school education," "teaching," "case studies," and other specific keywords that you think would be relevant. Once you come up with a list of journals, go through their website carefully and see if they publish case studies. Here are a few journals that I came up with:
- International Journal of Teaching and Case Studies
- International Journal of Educational Research
- The Journal of Educational Research
Note that these journals are just examples. You will need to evaluate whether these journals are suitable for your paper. Also, please be careful to avoid predatory journals and publishers and make sure that you are assured of the journal's reputation before your submit your paper.
Here is an article that will guide you on how you can assess whether a journal is reliable: Think Check Submit- The checklist that helps you choose a reliable journal