My iPhone SE won't turn on?

I have an iPhone SE, and it won't turn on. Whenever I try to take a screenshot, I can hear the shutter sound and whenever I plug the device in to charge, I can hear the little beep when it lets you know the device is charging. The only problem is that it's stuck on a black screen. Does anyone know how to fix this?

Unfortunately you'll have to take it into the Apple store to get it fixed unless you want to risk ruining it more and spending money on fixing it yourself (trust me this has happened to me before). Take it into the apple store depending on the wait you'll get it done in an hour or so and if its your first time taking it in they will do it for free as a curtousey.

Is it old? It may well be long gone. Go to the apple store. Whether or not it is fixable and whether or not it will be expensive, its the only place that will properly get it fixed. You may just need to invest in a new iPhone.

Hold both the power and home buttons for around ten seconds, until the Apple logo appears.
Only do that with it connected to external power and after it's been connected for at least two hours.

It's a common thing with phones and tablets if the battery gets completely flat, the RAM content are lost and the phone can't "wake up" as it's trying to load random junk.

The two button reset forces it to start up as if it were shut down properly. It does not delete anything.
(For later iphones an android device it's the power button plus either volume up or volume down).

I'd check with an Apple Store about that