I’m Transitioning From A Full-time W2 Employee To A Part-time 1099 Employee And Have No Idea What I Need To Do.

I work and reside in California. I’ve been a full-time employee of this company for several years, but this summer I had a baby and have asked to be reduced to part time so I could stay home with my child. The company has agreed to do part-time, but is transferring me to be a 1099 contractor. I have no idea what this entails. Do I need an LLC? Am I still covered under my company’s E&O insurance or do I need my own? Am I going to have to pay extra fees for this? If it’s part-time and the fees or taxes are super high, I don’t know if it’s even going to be worth it. I’ve only ever been a W-2 employee so I have no idea what I’m doing. Any guidance would be greatly appreciated!!