When I first started my business, I researched how best to market myself and where.
So many articles I read stated that it had to be all or nothing basically. It was really overwhelming, more so because I didn't use any of the platforms other than Facebook (and that was only to catch up on what friends and family were doing).
It too hours of my time, thinking of what I could post, was it interesting, going into different groups and trying to engage so I could encourage traffic to my website.
It was EXHAUSTING! With little to no benefit.
Until I attended a free training day at a local library. The lady who delivered the training was from a marketing background and she explained that not all social media platforms are needed to be successful.
If you product or service is photo based or easy to adapt to image based content, then Instagram is great for you. If it isn't, don't use it! Likewise, if your content is more wordy, then Facebook and/or Linkedin might work better (although images are still helpful on these platforms, they are more flexible). It was a great relief to be able to concentrate on a couple of platforms, which reduced my stress, freed up my time but more importantly allowed me to create better content.
My advise to any new or small business is to only use platforms that are most suitable for your product or service, keep the content interesting and relevant, which you can build gradually.
I hope this helps you when you are looking at where to start and what you should do!