If you want to build your Instagram audience, and maximize engagement in the app, you need to start with the basics.
Building an effective profile is the first step, while posting consistency is also critically important, so you need to map out an upload schedule, and stick to it. It's also worth trying out the different content options on the platform, like Stories and Reels, in addition to feed posts. Some have suggested that Instagram gives priority to profiles that use all of these features (particularly the newer ones), but at the least, it broadens your potential content exposure, and gives users another way to find out about your brand.
It takes time to build a solid IG following, but by covering off on the basics, and building from there, you set yourself up with the best opportunity to maximize your return.