The first thing you to get right is your brand voice. By ‘voice’ in this context, I mean the messaging you use to represent your brand. This includes the wording and images you create for your social media profiles, the copy you write for your posts and ads, the words in the about/bio section on your page, etc.
You need to write all of these using one distinct voice. The writing style and words you use for one post should match the ones you use for other posts on all your social media channels.
Do you want to be more conservational sounding? More formal? Or perhaps a combination of both?
The important thing is that you choose one style and stick to it throughout your various social media campaigns.