Sometimes they talk to you, friendly chatter or if you get pulled for whatever reason, sometimes random, they may tell you to stay behind a line while they do a swab or check something out in your bag. But don't freak out, they're usually pretty disinterested and just want to move along.
The most common advice I see is that they're not concerned about drugs, just don't be stupid with it. I've stupidly walked through the xray scanner with half a bar in my little jean pocket. The xray indicated something in both pockets. I emptied my big pockets and he patted me down. Another time, I had an oxy in my pocket, got randomly screened for a wanding/patdown. They didn't find it. That was stupid of me to risk it though. I've also had the back of my hoody set off the detector like 4 times. They just tell me they're going to check it.
I still get a little nervous, even if I have nothing illegal. I'll take some xanax beforehand. But I've had pills, drugs, weed, thc vape juice, e-juice, and multiple bags and containers of kratom that looked sketchy as fuck, albeit not all at the same time, but close to. I told them the kratom was tea and she said, "that's all you have to say." and sent me on my way with a smile.
But just make it blend in with food or other pills, like a vitamin container or something. It's always a relief when you get through and realize how easy it was.