You can download an application called "Root Checker" that gains root access to your device and tests if it's rooted or not. You can easily understand with that way if it's rooted or not. I can understand with that way and it's extremely easy.
There are a lot of applications called Root Checker but that doesn't matter just install one and you're good to go.
After doing that you can understand is it rooted or not.
If it's rooted you can use every application that requires root with the device you're using.
If you're device is not rooted open the recovery project you've installed (on Samsung devices press the volume down+power+home button at the same time) and from there wipe the data. Then reboot your phone from the main menu of the recovery project and press volume up+power+home button to open the download menu.
WARNING: THE METHOD EXPLAINED HERE ONLY WORKS WITH EVERY SAMSUNG PHONE. AND IT WILL NOT WORK WITH OTHERS. IT CAN WORK BUT NOT SURE ABOUT IT. YOU CAN FIND MORE INFORMATION ABOUT THIS CASE ON OTHER WEBSITES.
Connect your device to your Windows Computer and using Odin you can flash the necessary files including SuperSU to the device. And after doing those just reboot and bang, your device is rooted successfully.
Max Lee can help you on his website (highonandroid.com) that prepares cool articles about rooting.
You can also prefer The Unlockr that you can find on youtube and theunlockr.com.
Both prefer nice videos that can be helpful to you.