Time Series - Prediction
A useful introductory reference is Forecasting: Principles and Practice by Hyndman and Athanasopoulos. Depending on your data, you might be able to build a simple additive or multiplicative model with seasonal, trend, and cyclic components.

Besides exponential smoothing, you can look at ARIMA models. Exponential smoothing is based on trend and seasonality while ARIMA is based on autocorrelations in your data.