First off, you live in Johnson County. This is important to know so that you know what to look for when the server weather alerts pop up on the TV. Its probably a good idea to install some sort of weather app on your phone so that you know what is heading your way and you can be prepared. Those apps are also great in case you can't hear the sirens go off. Also, you will hear about Tornado Watches and Tornado Warnings. Watch is more severe that Warning but you will hear both a lot this summer. Just remember the bigger the word, the bigger the threat.
Second, know where your safe room is. Typically it is the lowest, innermost room in your house. It could be a bathroom or a closet (like it is at my house). You just want to make sure its a room without windows. It also may be a good idea have some non-perishable snacks, like granola bars, and water bottles down there for emergencies. Our safe room is a closet under our stairs in the basement. We have an emergency pack for each member of our family with a change of clothes (and diapers for our little guys), water bottles, granola bars, flash lights, first aid kits, a crank radio to listen for weather reports in case the power goes out and some toys to keep the kids busy if we have to stay down there for a while. I'll be really honest, in the last two years, we have sat in there maybe once or twice. We ride out most of our storms down stairs with the news on waiting for the all clear. However, its nice to have the reassurance that the supplies are there, if need be.
There are some great resources online for more information about severe weather safety. You should check them out and educate yourself when you get some free time. The more information you have and the more prepared you are, the less scary the storm will be.