Brand new galaxy s7 edge is extremely slow and lagging.

Just got a new s7 edge two days ago. My boyfriend got one as well, but his is well over a month old. We have the same service provider. But. Mine is extremely slow. His is a million times faster than mine. When i type in certain apps, nothing will appear and then all at once all of the letters i presssd will get big. It takes forever to load pages, and lags so much in general even when im not using the internet.

Any ideas? I am using the Arrow Launcher, and the apps i have installed are as follows:

Facebook, instagram, snapchat, clean master, messenger, hello, TD ameritrade, yelp, spotify, soundcloud, pandora.

Also, for some reason when my phone restarts or randomly the good lock setup will pop up when trying to unlock my phone even though arrow is set as my default launcher. Please help!!