Custom dataset making and training.

Dear all, I am a college student doing my final year project. I want to train my custom dataset, although there are some tutorials for making dataset, I never success. I know there are some platforms can train slowfast, such as Pyslowfast/Detectron2/mmaction2... and know types of action dataset (kinetics/AVA/UCF...). Is there any kind person can give me some hint about making custom dataset (any kind of dataset is fine) and training? If you can, I will be very appreciate!