What is the day to day like in the 1-509 OPFOR?

From my time at Polk, you will stay busy helping to train the troops. Happy 509th was in Kandahar when we got there. Nice knowing a unit from Fort Polk and seeing people you know.

We spend half our time in garrison and half our time in the box usually. Sometimes we will get a month break between rotations sometimes you'll get a few days. It's busy either way. It's still a FORSCOM unit so there's still groaning requirements we have to meet as well as rotation prep. You can go to almost any school you want outside of rotation and you'll have plenty of chances to jump. It was my second choice originally i bumped it up to my first. Been here about 3 months and it's been busy but fun. I moved it to my first choice and I'm glad I did.

Not sure about the day to day.
I was an OC/T assigned to First Army and worked at Ft Polk a couple of times as an OC/T augment. My OPFOR experience was supervising the OPFOR during some of our lanes.
From my experience, when you first arrive, you should be given training with different devices such as IED simulators and tactics training.
You will likely be assigned a variety of scenarios to enact while a unit is in the box such as convoy ambush.
In short, there will be a lot of waiting and preparation with short engagements and maximum safety.
Good luck