Becoming official/insured/protected baking cakes for others?

Hi all, I’ve been doing some cake making as a hobby for about a year, I’ve not had any lessons but built up a collection of cutters and other decorating tools etc. recently a local photographer friend asked me to provide her with cakes for ‘cake smash’ photo shoots. I’m really pleased she’s asked me but a couple of people (one being a local cake maker & tea room owner) have brought up the fact I’m not officially a business or have any insurance or certificates to back me I up if anything went wrong etc, It’s really thrown me and I’m worried now as the cake smash cakes are for young children and I’ve built up my collection of tools and equipment I don’t want to stop making the cakes.
I think my questions are…

How easy is it to make your ‘hobby’ in to an official thing..? I’m not good enough to quit my part time job I just want to keep it as a hobby but be more protected and safe.

What courses/insurance do I need to cover myself?

I hope this makes sense I’m not very good at getting things down in words!
Thanks
Lucy