Here are a few, hopefully helpful, words about the capital of Cambodia.
If you need a visa, and you’re eligible to fo so, get one online using the government e-visa website. There is a commercial site, but go with the .gov. Print out a couple of copies. You may also qualify for visa on arrival, which is fine but will hold you up on entry.
You’ll almost certainly be taking a tuk-tuk at some point. You should get a face mask if you plan to do it often, unless you like to inhale carbon monoxide.
Almost all prices are quoted in US dollars. Get some greenbacks in mixed denominations, especially ones and fives. The standard taxi fare from the airport into the city, at the time of writing, is $12.
Things are cheap. Outside of a fancy hotel or restaurant, you shouldn’t pay more than $10 for a meal and $2 or $3 for an alcoholic drink.
People are friendly and helpful. Even those wanting to sell you something aren’t too pushy. But take normal precautions against pickpockets and con artists.