When you finally get the account of the victim, you can do whatever you want, but... there is a tip that you should follow. If you wanted the information to spy on them (which is the most common), you should look at everything you want but without changing anything, because you don't want to alert the real owner of the account that maybe you have access to their account.
If you do it right, you could get the access to their personal information, conversations, notifications history and to their photo gallery and videos, in which there might be content that is not public for everyone and might be interesting.
You can download a copy with all the information of your victim easily by clicking here. With this information, you'll be able to see and read all the things that this person has done from the very beginning until today, such as posts, photos, shared videos, messages, conversations and a lot of other info. This is the best way to know what this person is doing without using expensive or useless hacking software.