I am doing the sales forecast. I found the trend and seasonality manually for my time series data. Regressed time series data against the trend and seasonality and found the residuals. The residuals doesnt have autocorrelation(is this expected?). Verified the ACF and PACF plots and found no significant variables. What model to fit for the such residual data? It is normally distributed(confirmed using shapiro test) Any kind of guidance to move forward will be really helpful. I am new to the time series modelling
Please advice. Thanks!