A:AnswerBasic answer: That's all you need.
But I do have to say this, unless you have a newer, name brand smart phone(an iPhone 7 and up, or a newer Samsung should do it) I really wouldn't recommend you buy this headset. See I have a cheap Samsung and you can clearly see the pixels when using it. Trust me it will be unenjoyable if you can see pixels. I have never tried any games. The games would need to be downloaded and the controller synced to the phone. Also there is no wired connection and it may be painstaking to add headphones.
All in all I think your child would like this product if he is newer to technology. This was my first VR headset and I have to admit for twice the money I could have had a better experience.
A:AnswerI am using it with an Iphone 8 no problem. The SE appears to be a bit smaller, but in using the headset, it should have no problem. There is a cradle that expands or contracts to hold the smartphone.
and yes, my boys and I love using it for VR videos and some games
A:AnswerI have an iPhone 6. Mine was the same way, then I started leaving my phone in it’s case before I put it in the headset. Now the button works. I guess the phone just needed to be a little closer to the button. If your case doesn’t fit in, maybe you could put something thin behind the phone, like cardboard?
A:AnswerYes, this controller is compatible with the iPhone X. It even works if th phone has a case but it has to be a thin case like the Otterbox Pursuit.
A:AnswerNo, it only works with small number of apps. I have tried to use the control to play vr videos on YouTube and many times I have to do it manually.
A:AnswerVRChat is a PC game, the best and cheapest headset is and Oculus, which will cost you from 400 up to 1000 dollars. You'd also need a VR ready GPU.
