Get Likes and Followers without botting

I started an new agency account in instagram. I want to grow that acc without botting.
I want to boost that account legitimately so i can use it as a second acc for a new company.

I can purchase promotion but what should i use?

Are there other methods?

From what I have read on the forum Instagram Ads seem to work super well in organically growing your account. I would also recommend checking out the "Gary Vee $1.80" method. Other than that my best advice would be to optimize your username, profile pic, bio, story highlights. Then post high quality content both on your stories and feed. Finally respond to every comment on your posts, reach out to other accounts your size to collaborate/shoutout for shoutout, like pictures from hashtags relevant to your niche, and try to interact with your target demographic as much as possible.