Basic is the equivalent to what we play at WDW. If that event is challenging and fun for you, that is what you should sign up for. It should be thought of as the regular version of the game.
Advanced is for teams that want an extra challenge. A few additional quests, less instruction, more competitive (and slightly more expensive) and NO HINTS AT ALL. I would say you do NOT want to level up unless you feel that Basic or the WDW games are too easy for your team and you tend to finish early. Advanced is no joke, it is hard and the teams that play it are VERY competitive.
Historically, the Disneyland events have frequently had two divisions. In the early years, they were Quests Only/Quests and Trivia. Later we added trivia to both and made Advanced as the more difficult division.
We have also occasionally done a “101” division which is an easier version of the game, more instruction, hints, partial credit.
Does that help?