Welcome to TMC!
You're asking about a test drive for a new (2021 or later) Model X? They're not even in production as of early September 2021 (aside from test / pre-production cars). The first production cars are likely to go to people who have placed orders...service centers and galleries won't get cars to give test drives until well after customers have taken delivery (IMHO). Basically there's no way to get a test drive of the not-yet-released Model X at the current time.
Note that to place an order is "only" $250, not the entire purchase price.
Bruce.