Downloaded YallaGo before the trip because everyone says street taxis will double you. It will not send the SMS to my US number.

SMS will not hit a US number. Need a Syrian one. That part is not a rumour.

I flew Beirut, van to the border (~$30 with two other people, private taxi wanted $100), paid $200 cash visa, next day walked to an MTN shop, English-speaking guy, SIM was 400,000 SYP. After that YallaGo worked. Drivers call you, I do not speak Arabic, I just stand where the pin is and look like an idiot until they find me. Still cheaper than haggling a street taxi, those guys will double you.

Download YallaGo Pro. The old app is dead. Pro also works outside Damascus, the old one did not.

You can get a tourist SIM with a passport, I did. Some people still say you need a Syrian ID. That was maybe true for a while. Try MTN after you have the entry stamp.

Landing DAM at 7am: I was told the SIM shops might be shut and YallaGo is useless until you have a number, so budget $25 for the airport taxi and deal with the SIM in town. Fog delays are a thing too.