Need cash when I land, best place in Turkmenistan? Airport or places in the city?
My advice is to skip the exchange counter altogether. Most importantly, you need to bring cash with you. International cards are not accepted at any ATMs or businesses. The best place to get cash is to find a reputable money changer in Ashgabat. The local currency is the Manat, but US dollars are widely accepted and preferred. Just make sure to get a good exchange rate, as you will not have any other options once you're there.
The airport exchange counters have awful rates. Your best bet is to find a licensed and reputable currency exchange center in Ashgabat. The unofficial market rate is much better than the official bank rate. I've used places in the city and got a good rate. You must have US dollars with you, and it's best to have clean, new bills. Don't exchange large amounts at once, and always count your money in front of them.
Don't even think about using the airport exchange. It's a complete scam. You'll get ripped off with their bad rates. The best way to get cash is to go to a reputable money changer in the city. The country's economy is in a difficult state, and you'll get a much better rate for your US dollars from a private exchanger than you will from a bank. You must have US dollars with you as your card will not work at any ATMs.
You should absolutely avoid the airport exchange counters. They give terrible rates. However, you also must know that international credit and debit cards do not work in Turkmenistan. The only way to get cash is to bring it with you, preferably US dollars. Your best bet is to find a reputable currency exchange center in Ashgabat. I've heard the exchange rates are much more favorable on the unofficial market than from the state bank. Just be discreet and count your money carefully.