I haven't read or run the Dawn of Artifacts adventures, but I can give advice on the other points.
On character creation.
I've seen two ways of doing it that works well for new players.
A: Restrict them to the core book for initial characters. While this helps learn the basics before expanding outward, I personally find it too restrictive as some things in the core book (negative qualities for example) are severely lacking.
If you do this, I recommend allowing the players a chance to "rebuild" or "re-roll" their characters when you decide to allow the other rules to be used. (By rebuild I mean build the same character with access to all the rules. By re-roll I mean make a new character, but keep the earned karma (and possibly nuyen).)
B: Read all the books with CC rules in them cover to cover. When players are making characters, make suggestions to them that are as efficient as possible. This works even better if you have a veteran player willing to help out as well.
Also, make sure to devote an entire session to character creation and place emphasis on things often ignored by first time players: backstory, negative qualities, edge, and contacts.
In general, I have a three session rule. I'll allow you to tweak your character for the first three sessions of the campaign.
I can't stress enough how valuable the Runner's Toolkit is for a new group of players. I haven't personally picked one up yet, but it will be my next purchase.
As a new GM that also has new players, you're at a bigger disadvantage than most. If you have a player that grasps the rules faster and better than most (most groups have one), appoint him rules assistant. If you're unsure of something have him look it up for you real fast.
Also follow Big Peat's advice especially:
- Read the adventure
- Know the characters (get copies of their sheet)
- Talk to the players and encourage them to talk to you
- Aim at what you all enjoy
- Be fair and consistent and talk to the players if you're not sure where that lies
- Ask more questions here if you come unstuck.
Copies of their sheets help you balance encounters against them. Reading the adventure lets you help things run fast and helps you tweak any overpowering encounters in it. Being consistent keeps all you players happy and feel that there are no favorites. And last, but in my opinion most important, talking to your players and making sure they have fun is what the game is about. If people aren't having fun in a game there is no reason to play.
As for the first run, a lot of people suggest Food Fight, I'm not a fan but it will help your characters learn the rules. I usually use a self updated version of Silver Angel.
Brief Summary:
A group of runners is hired to break into a research center and steal a file named "Silver Angel". There are many ways to get in, from the flashy lets bust through the front door, to hijacking the shipping companies truck that makes deliveries that night.
However the run must go down at a very specific time and if the group lingers, an alarm will go off even if they haven't done anything wrong. Of course the group doesn't know the last tidbit, so it can make things interesting

.