Do you have a smartphone and use the IG app?
You should do that if you don't as you can like peoples things,
comment on things, follow people etc much easier
follow people in your niche, follow their followers etc
and comment on big IG account posts
say something nice about it and people will naturally follow you.
You can do it online too
but the app makes it easier when you're not working at your desktop.
I have an IG account I'm working on now
and that's what I do from time to time when I'm not working on my desktop.
I pretty much never login to it on my desktop
unless I'm authenticating login on another site with it or something.
My followers and post likes are increasing by the day and I don't really do that much with it.