Trying out Sql Injection is important when you want to see if your site is vulnerable. My opinion is trying all the popular script there’s in the web so you can see from the point of view of the attacker. I tried this so all my website can be protected from sql injection.
First you need to find a target, just try to find in google inurl:id= or try looking around in Google dorks well make sure you have the permission of the owner of the website. or if you have a local webserver you might test it there but for me somehow I couldn’t test it on my local so had find live one.