When I pull down the top part of my screen to say, turn on the torch, it isn't there and nor are any of my other icons. The Wi-Fi symbol has also disappeared from where it should be on the left side of my screen to and I'm not sure why either, yet the internet still works. Anyone have any solutions to these? My phone is a Samsung J3 2017
Well that's not good !
Hopefully this is a minor glitch which a soft reboot may help via turning the phone Off and On.
Put the phone in Safe Mode which disables the downloaded apps and leaves the stock ones Live to see if a rogue app is causing this or maybe a download theme or 3rd party launcher.
If this does not remedy the situation and all your other preference settings look Ok and no rogue app is causing this then Back Up and Factory Reset as a last resort.
Also a Samsung Experience Store or Samsung Service Centre can take a look.