Use the collected cookies. After this, you can use the cookie information, which should be saved to your website, for whatever purpose you need.
Method 2 of 3:
Executing Injection Attacks
Find a vulnerable site. You will need to find a site that is vulnerable, due to an easily accessible admin login. Try searching on your favorite search engine for admin login.asp or admin login.php.
Login as an admin. Type admin as the username and use one of a number of different strings as the password. These can be any one of a number of different strings but a common example is 1'or'1'='1 or 2'='2.
Be patient. This is probably going to require a little trial and error.
Access the website. Eventually, you should be able to find a string that allows you admin access to a website, assuming the website is vulnerable to attack. Then, logged in as an administrator, you can perform further actions, such as uploading a web shell to gain server-side access if you can perform a file upload.
Method 3 of 3:
Setting Up for Success
Learn a programming language or two. If you want to really learn how to hack websites, you'll need to understand how computers and other technologies work. Learn to use programming languages like Python, PHP (necessary for exploiting server-side vulnerabilities) or SQL, so that you can gain better control of computers and identify vulnerabilities in systems.
Have basic HTML literacy. You will also need to have a really good understanding of HTML and JavaScript if you want to hack websites in particular. This can take time to learn but there are lots of free ways to learn on the internet, so you will certainly have the opportunity if you want to take it.
Consult with whitehats. Whitehats are hackers who use their powers for good, exposing security vulnerabilities and making the internet a better place for everyone. If you're wanting to learn to hack and use your powers for good or if you want to help protect your own website, you might want to contact some current whitehats for advice.
Research hacking. If you're wanting to learn to hack or if you just want to protect yourself, you'll need to do a lot of research. There are so many different ways that websites can be vulnerable and the list is ever-changing, so you will need to be constantly learning.
Keep up to date. Because the list of possible hacks is ever-changing, and new vulnerabilites are discovered, you'll need to be sure you keep up to date. Just because you're protected from a certain type of hack now doesn't mean you'll be safe in the future!