The access queue

At busy times the market lets visitors in in waves rather than all at once, and the queue page is the waiting room for that system. It is served by the market itself, from the .onion address you opened. Two consequences: it means the address you copied worked, and you are closer to the market than the page looks. And a queue page on anything that is not an .onion address is not the market's queue.

On a good network, tens of seconds. When the market is busy or your circuit is bad, several minutes. It is slower at peak hours than in the middle of the night, and 'peak' is spread across time zones, so it is often just slow.

The rule of thumb: five to ten minutes with zero change is not waiting anymore, it is stuck. Close the tab, open a new one, or take the next address from the list above. A stuck queue usually clears by moving, not by refreshing.

Refreshing does not move you up the queue. It drops the connection that was being built and starts a new one at the back of the line, so every impatient reload costs you a minute or more. If the page has genuinely stalled, the move that works is a fresh tab with a fresh connection, or the other address. New circuit in the Tor Browser toolbar (the onion icon) is the third tool, for when the address is fine but your route through Tor is the problem.

If all three addresses above fail from a working Tor Browser, the market is down or your network is the problem, and there is no status board that will tell you which in advance. The test is the same one you already did: open the address, wait the queue out, try the next address. When it comes back, it comes back on the same three addresses, nothing to re-learn. The FAQ covers the 'is it down' question in more depth.