MacBook Air M2 Midnight 2022 - upgrade RAM

Hi, I am looking for a MacBook Air Midnight 16GB - M2 (2022), but this configuration is only possible to pick up in January, however, I will not be in the US on this time. 8 GB RAM is available inclusive on Best Buy, and it is not the specific machine that I need to. So, if I buy 8GB it would be possible to upgrade? I will be in US from 24 to the beginning of the year, and I would like to buy it as soon as I arrive. Does anyone know if there is another place next to LA area where I can buy this specific machine? thx.