Regarding the game time that comes with TWW - only the Epic edition provides the 30 days of additional game time with it. The base and heroic editions do not. But given the sale going on right now it’s a good time to consider the base edition at least.
The base edition is $24.99US right now (on sale). The Epic edition, the one that provides 30 days of extra game time, is $44.99US (on sale). The subscription itself will give you access to everything in the game minus the current expansion. The choice is up to you. Either way, enjoy your time in Azeroth!