It depends on how much you use the phone. The first thing I'd suggest is to uninstall any apps you don't need. Also try disabling (or uninstall if it's an option) any factory or carrier installed apps that you don't need. These two steps will stop unwanted apps from being initialized in the background.
Not having used that phone specifically, I can only give a generic set of directions. Go into your main phone settings, often accessed by swiping the notification bar down and tapping a gear icon. From there, look for a setting labeled "application manager." That will show you every app installed. Find the apps you don't want and tap each one. In each app setting, you should see an option to disable and/or uninstall.
While you're in there, you can try clearing app cache. If your storage is getting full (possible at only 16 GB total storage), that can sometimes cause some lag. Deleting old pictures you no longer want, old text messages, and anything else you don't want can help if this is part of the problem. Text messages especially can take up a lot of hidden space if you don't regularly delete them. Your messaging app may have an auto delete option, only keeping a set number of messages.
There's also the option of deleting the system cache, but you'll need to look up the directions for this as it can be different for every phone. If you want to go with the nuclear option, you can try a full factory reset, but then you're starting from scratch. Yes a reset can help, but I usually leave it as a last resort because it may not even fix the problem depending on your usage.