Hi, and welcome.
Rooting gives you control over your phone, but you void the phone's warranty and you run the risk of bricking your phone--in other words, turning it into a paperweight.
You can avoid bricking by readingn*everything* about rooting for your particular device (and never, ever use something that does not say it is for your particular device) and not proceeding until you understand what you have read.
HERE is the rooting section for your phone. Feel free to ask questions in that folder about anything you don't understand.
You can free up a lot of space just by clearing the cache. There are lots of free one-touch cache-clearing apps in the Playstore, or you can go through each app in settings and clear the cache that was. Clearing data is helpful, too, but be aware that clearing the data removes any personal data in the app. If it is a game, you have lost your progress, but if it is Facebook, you will just need to log in again and everything will be fine, so be mindful when clearing data.
Also, if you are rooted, you can clear out tombstone files. Whenever an app crashes, it makes a file called a tombstone, and sometimes they can be quite large. If you root, it is worth looking to see that is in the tombstone folder (I got back many mg the first time I did). The files can't be used, so you may as well delete them.
hope this helps.
