[luiz187]

I am new at hacking but I was wondering, you always hear about people taking down websites and or editing them? How do you do that?

[Illuminatiž]

It's easy hacking websites.
Go to the website you wish to hack, right click and click on "Inspect Element" and destroy their site!!!
Good luck, OP. Shit is magic.

[Hopeful Goods]

Well, you would need to find some way of gaining privileges.
There is an exploit out for Apache systems on debian and ubuntu. You could scan for those and mass deface if you want.

Some people jack the domain, which means they social engineered the hosting company into letting you access their DNS records and edit what the domain shows.
You could also find an exploit on the site. Look into LFI, RCE, RFI, SQL Injection, ect.

I hope this helped. Good luck!