Predicting with multiple time series
I would recommend looking into FBProphet.
It's a good starting point for automating the creation of forecasts. It's very easy to use, and often produces better results than classical forecasting methods (ARIMA, Holt-Winters, etc.) right out of the box.
The default settings offer an additive or multiplicative model, comprised of trend and seasonality. This can be a combination of daily, weekly and yearly seasonality patterns, with the option to add custom patterns if required. Holiday effects can also be tracked using the built in holiday calendars, which again can be customised.
This is generally used for data with no external regressors, just a datetime and a measurement. However, external regressors can be configured, to influence the outcome of the forecast.