LLC or Not LLC, that is the question

Hi, Coaches. My goal is to start a coaching business and I am feeling unsure about a couple of things. Because I have a 9-5 job, I would like to to do coaching part-time until I earn enough to part ways with my day job. I am still finding it a challenge to identify what my niche is, but I have been reading and brainstorming in hopes that I will discover my niche could be.

My question is, should I start an LLC or DBA for my coaching business this year? Or is this a question to ask an accountant?

Thank you!