Choosing the kind of posts you want to make on your profile really depends on how you want to grow.
You can post other people's content and give them credit, this does not protect you legally from copyright, but it protects you morally, most people who post content will value your report as publicity and will not take it down, unless you post cat videos, those are mainly into the hands of copyright trolls which will ask you for money in exchange for not deleting your page
The positive in this is that you can post content that is already tested and will go viral.
On the other side, if you can generate really high quality content, you could be the one receiving reposts, this will make your page grow exponentially more, but only if you generate good content, otherwise you'll just get nowhere.
The positive in this is that if your own content goes viral, it will go viral for years to come, since people will continue posting it on their own pages and bring all of the traffic to you.
What i personally do is more risky. I go on other platforms where content goes viral (Reddit, Twitter, Tumblr etc. etc.) and i take that and post it as mine (after doing a background check to make sure the original poster is not on instagram). This way i get the best of both world, but if someone where to find this out, there is a small small chance they will ask for money.