How long is DnD Starter Set campaign and is it easy to string it with another module?

I’m pretty interested in to buy the DnD Starter Set to both get introduced to DnD and GM/DM for the first time.
Since I discovered Stack RP, I read a lot of DnD Q/A by curiosity and it really gave me envy to try it out.
I already played a bit as a player with a group of friends, and I’d like to DM this group as I’m a bit shy and I know them pretty well and can anticipate how they will act and can react better to this.

But even after searching for this I don’t have clear answers to these two questions :

  1. Given a party of moderately experienced player, how many hours the starter set campaign can last ? (at minus, without side quest/job, fights going well etc…). Prior experience with starter set would be really appreciated.
  2. After finishing this campaign, can I make my party “move” to another bigger module easily (keeping characters sheet) ? (this question is related, but don’t really answer if it is possible to make a transition instead of just start a new game)

All answers backed by experience with the starter set are very encouraged.