¡Holas!
I've found it best to group everyone together in some fashion. A "tourist survey" of The Edge (visiting places & rating them) for the Tourist Service, maybe as an exchange for a way to not be deported off AA; or a special team working for one of the factions, or all friends visiting together for someone's wedding i[/i] or a bizarre family-unit, all these work.
Then, most noobs could be gently pushed towards creating more "mainstream" (ie, realistic characters - like a scientist that has a special power/device, or a occultist touristing, or a reporter/jaded author who kicks ass whilst drunk). Evil reincarnated atlantean priests or ETs that wanna steal the isle from Kergillian hands could be allowed for more experienced players. This way, most noobs will be expected to be asking "the usual" noob/burger questions. Maybe a noob can play him/herself?
Remember the "tone." Best to make a "contract" that everyone signs & knows what to generally expect. OTE can be anything from a Dalí painting to the Eureka tv show (& all movie ratings in between - some parts of it are quite disturbing & some are downright silly!).
I'd say "sandbox" style works best, with minimum railroading (let the adventures gently & organically grow, or make it subtle for published stuff to be introduced) - the PCs will (at first have a lot on their plate - one hopes! - & will be checking stuff out. But remember, if you look closely, each barrio/area has some percentage of "stoppage/peril" that can help you detain them until you fill you can better control the situation, if you believe your outta your depth, that is...).
Also, check the PC sheets: check for interesting motivations & stuff that you know will engage the player &, deal with those. Maybe a tourist would be interested in visiting landmarks - so they will probably go to check the various monuments in different barrios... Then, you could roll on the tables or check for NPCs in those different locales & pick up their story ideas... Then you can take it from there...
The OTE books is pretty GM-friendly. Most of the info is quite visible &, if you fuck-up, then you can always let it stand & just keep rollin'. If the PCs catch your mistake, & you let the mistake stand, there's a new adventure right there. This is all from the advice in the GM's section.
I'd just wing it, usually. OTE should be tailored to your own point of view in every sense.
I was like you at first but once I started running the series I found out that OTE is pretty smooth.
HtH
T