Currently, I'm running some neighborhood kids (ages 14 and under) through the tier one Waterdeep adventures. We started with Once in Waterdeep and have worked our way through Dock Ward Double Cross. Only one of the kids (my daughter) has played D&D before. I was very happy with Beneath the City of the Dead. This was the adventure where they really "got it." It can be tricky to find that perfect adventure that introduces the tabletop RPG concept to a new player. But sometimes? A tiny dungeon crawl is exactly what is needed. This is a dungeon that can be easily run in two hours. The encounters and traps were interesting enough that the players were enthusiastic about the whole process. The encounters were well balanced. It won't destroy a tier one party, with or without a short rest. The decision making was easy enough that they weren't staring at me dumbfounded. ("Do you want to go during the day or wait until night?") That was sufficient to get them talking and figuring out what was best to do.
This adventure doesn't really work without also playing 08-03 soon after. It ends on a bit of a cliffhanger. However, the two adventures fit together nicely. I'll admit DDAL08-00 and DDAL08-01 don't feel as essential. If you have to choose, I'd just start with this one. And it saves time because the end of 02 is essentially the call to adventure for 03.
One of my players had lost a grandparent the day before, so I reworked it as Beneath the "City Garden," instead of it being a cemetery. I ran it as if it were more akin to Central Park—which worked fine. If you have young players who are sensitive to death, to me, this was an easy switch.
It was an easy adventure to run (always a plus for a busy DM). I was able to sufficiently prep in only 30 minutes. The players had a good time with it. What's not to love?
[5 of 5 Stars!]