I'm looking for some indications about the tuning of hyperparameters in building my double DQN. I have a time series problem (with about 2000 observations and no terminal state, I have to max the rewads) so I decided to define as an episode a subsequence of N observations (from that dataset) starting from a random point (e.g. from the 245th period to the 245+N period). So here the first doubt: should I run more episodes with a smaller N or vice versa? In a different context I would make some tries, but here it takes a lot of time.
What about the length of the batch and the step when updating? Are there any generally accepted rules?
The final hyperparameter that I don't know how to choose is the moment when updating the target model weights. I know I should do that rarely, but I do not find any specific rule (if not very high threshold, that I doubt in my problem will be reached).