Need advice from professionals please !

Someone threatened me that they will pay to ban my acc, the next day I’m copying and pasting comments in my engagement group ( below 20 acc ) on ig and I suddenly get banned. And it does say this when I try to login so do you think the guy banned me or is this actual Instagram that banned me ? Basically could the people that ban accs lol help me out and tell me if it looks like this when you ban someone’s acc

No one can ban your acc but IG.
So, he may have known about your engagement group and reported, or he actually works on IG and may have a reason to threaten you.
Is this person a competitor?

Yes they really can. They are scammers so they have this bot that bans and I bans accs. And I just need to know if it’s him or IG. I did buy fake followers but it never got me in trouble before

Whoa this is scary - where did you get the threat? In your inbox?

well, Instagram is running mostly on automatic block/ban system that responds to user reports as well. thus, hypothetically if I have a big network of accounts, or even bots, I can use them to report your account for spam (for example) and that might trigger the automatic system to ban you. The only option you have at that point is to contact Customer Support by clicking on "let us know" and proving them that you are an honest IG user and did nothing wrong. Then someone will look at your case manually and decide if you can be unblocked. Very simplified explanation, but you got the point