Increasing your followers on Instagram is easy. You just need to follow the footsteps of popular Influencers.
Don't indulge in buying followers, as 99.9% of them are fake and won't engage with your content at all.
Make sure you have an attractive and clear profile picture. Also have a well defined bio. Use of emoji's is encouraged to grab attention.
Before going all in with your promotions, ensure you have at least 12 posts on your timeline. So when people see your profile they engage.
After optimizing your profile. Start following as many people as possible. A good strategy would be to follow relevant people to your Industry or demographics.
Make a daily post on your Insta timeline. If possible, make reels, they are being pushed by Instagram big time. Also, ensure your post timings are constant daily.
Do take a look at the trending topics and see if you can incorporate them in your Insta reels, stories, or posts. This can bring you in front of more users.