Welcome to TFP! You're gonna love it here.
To get you started, you need to obtain your own testing kit and avoid pool stores altogether.
See this article
Swimming Pool Test Kits Compared - It outlines the recommended test kits we all use here. I have the TF100 from tftestkits.net and find it to be the best value for me. I also use the speedstir, which I highly recommend. It makes testing much faster and more repeatable.
Order one of the recommended kits, then download the PoolMath app.
Use PoolMath to calculate 5PPM of whatever strength liquid chlorine you have available to you. You're in Iowa, so I'm sure you have a Menards. They sell 12.5% liquid chlorine labeled as Pool Shock. Add 5PPM worth of liquid chlorine to your pool EVERY DAY. NOTHING ELSE. Do this until your kit arrives. When the kit arrives, run a full set of tests and post the results for our experts to guide you on the next steps.
You will likely need to perform a SLAM. I'll link that article for you. Take some time and read this article so you fully understand what you're going to need to do when your kit arrives. -
SLAM - Shock Level and Maintain
Again, welcome to TFP. We do things a little differently than the rest of the pool industry. There's a small learning curve, but you'll quickly figure it out and your pool will look better than it ever has. You will also save a ton of money by not throwing expensive magic potions into your water at the recommendation of some kid who possibly asked you if you want fries with that just last week.