First, let me welcome you to our site on the walls of all other people here
For the hacking basics you may want to get hand on some different techniques.
There are many, but here are some of the most popular:
SQLi : Structured Query Language Injection is one of the most common vulnerabilities found these days. There are multiple tutorials in the forums. Just search for them in the Website hacking section.
XSS: Cross Site scripting vulnerabilities stand as the second position of mostly found vulnerabilities. It's basically a method to inject malicious javascript to the site, so it will allow you to for example steal cookie files, or even spawn a shell on the site
RFI and LFI : Remote File Inclusion and Local File Inclusion are one of the rarest to finds today. They basically do not filter which website have been requested and allow you to include other pages from other websites, or include local files that allow you to spawn a shell on the host.
All of these can you find on this forum under Website hacking section. These are the most basics you can find today, I think (feel free to correct me if 'm wrong)
Again, welcome to the site