I'd say that as a new player you do NOT want the Road to 70 buff.
It really messes up the leveling pace, and causes you to outlevel content sooner rather than later unless you know how to split up xp among several classes.
If you skip sidequests you will also miss out on a lot of quest rewards, which can easily lead to you having substandard gear.


If you really want the Road to 70 buff there is only one way to get it on a character:
Start a new character on a New or Preferred world. (Currently there are no New worlds.)
New or old player does not matter - all characters created on Preferred server gets the buff.
Note that such characters cannot be transferred to another world until 90 days have passed - at which point the buff will normally disappear as well.