The included model adventure, lost mine of Phandelver, includes not only a very well written adventure but a really detailed set of adventure locations, NPC's and a town which can easily be used as is for a home base, adventure location and starting point for an excellent campaign.
Reading through the module fully before playing it is something I would recommend more highly than with most modules. The amount of NPC's with little quests and information to be gained is quite extensive.
If your players are module runners who point form NPC talking and hack their way through things quickly I would expect about 10 hours of play time from the included materials and they would most likely miss many of the side areas.
Real role play actors will find they can play in the setting provided for as long as they like. You could easily expand on the npc's with their given group affiliations and background.
New players would spend about 20 - 40 hours learning the game as they go and doing as new players do. Really with this game the style of play will be the determining factor.
Using the forgotten realms specifically the area around Neverwinter was a wonderful choice. There is so much back story, history and old supplements that can be used with this. Specifically the map which came with the Neverwinter book is extremely useful. Neverwinter Campaign Setting