My Galaxy S7 is lagging a lot? How do I fix this?

I just switched from the iPhone to the S7 Edge, and I've had it for a couple of weeks now, I'm having problems with it lagging when I type, or when I am listening to music and on FB or Instagram or something and the music skips really bad, It lags like crazy almost to the point where its unusable sometimes? IS this normal, how do I fix this? Should I take my phone back?
Added (1). This is my first android phone, so idk much about the Samsung phones.
Added (2). I can't even listen to music in peace without my phone lagging up and freezing up on me
Added (3). My friend says I might have a virus on my phone?

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