Default localhost settings
Over the past few weeks I have been trying to learn about building a LAMP server and followed countless tutorials. However it has made a little mess of my system, as I can no longer access localhost from a browser. I am suspecting it is /etc/apache2/sites-enabled/000-default.conf that I changed, and although I can see what I have changed, I have no idea what it said originally. I then tried something that I found online about recovering default set up files using dpkg which also did not work so now I have nothing. I want to go back to the default html page, whilst currently I am now stuck at a 404, which makes learning a little on the tricky side.
Is there an easy way to reset all this without actually reinstalling the whole operating system. This is on a raspberry pi, so there is nothing really important on there, but it would be nice to know what is happening and how to revert changes.