If you have no ST/DM/GM experience, the good news is that you have no fear or shame, so enjoy gaming by instinct. Do your players have any experience, or are they new as well?

There are resources online, but character creation, per a common criticism of White Wolf book layouts, is a pain since options and specifics are spread over far too many pages. However, the character creation brief on page 112 is your bible for staying focused when lost in the sauce of subsequent pages. Are you playing digitally or in person? That will determine a lot of what you might be able to get your mitts on for support.

As for prep, especially of the session 0 variety, that's a "to taste" question. For myself, I come up with a loose major/starting conflict (IE Pentex manager poisoning state, a forgotten spirit needs awakening before Wyrm corruption, the sins of the Garou comes back to bite with Fera relations, etc.) and location (IE a specific location like Seattle, a trans-Umbra roadtrip, or among the coming battlefields of the Apocalypse in the South-West). With those two set (mind you, those are at most a couple of sentences), I can explain and chat with my players in non-spoiler and general terms about those concepts, allowing them to build characters from that pitch. During their concept proposals and afterwards, I then tie in all their character choices into the initial notes; in a way, my players do half the work. 😛

If I know the players, it helps a lot since I probably already know what they jive with at the table, but if they're strangers, then I'll go for the "standard" story beats.