Yep retail investors (like us on 212) get access last out of everyone so the price is not going to be the same as the IPO price.
When the exchange opens trading for retail investors, they do so at the open price that the exchange has determined by matching incoming orders during a process called price discovery (I believe this happens manually on NYSE but some other exchanges have this process automated).
Price discovery basically involves the exchange identifying the best price to open at that will allow the highest number of trades to be done, by matching incoming sell and buy orders from institutions. So like the SNOW IPO today when people were quoting “looking at opening at $xxx for x million shares”, they are basing that off the price discovery info from the exchange.
Only when the price discovery bit is done does the exchange open up to retail investors (robinhood users, 212 users etc.) and then trading is done as normal.
Hopefully this helps a bit 
P.S. my knowledge on the specifics of the process once the exchange gets involved is pretty patchy and dated so pls anyone correct!