Source for gdp data https://fred.stlouisfed.org/series/BBKMGDP source for la data https://data.lacity.org/browse?q=Port%20of%20Los%20Angeles%20-%20Port%20TEU%20Counts%20-%20By%20Month&sortBy=relevance
source for GDP quarterly forecast https://www.philadelphiafed.org/surveys-and-data/rgdp
Alex suggestions, intrest rate lags, oil price lags. Use oil prices from previous quarter.