Reasons for setting up a legal business

This might sound like a silly question but what is the benefits of setting up a business legally rather than just working under a name you give yourself?

I am originally from the UK and moved to the states where I work as a personal trainer and trained my clients in a local park.

I then set up a LLC which costs $800 a year that I pay for CA tax just for having a LLC.

Right now unfortunately business is very slow so was thinking if I should dissolve the company and still work under my company name (maybe copyright the name so no one can take it).

Right now this year I have only made around $350 pounds and I do not see business picking up soon and the $800 is due in April unless I dissolve my company.

So with the fact I am right now making next to no money through my business what benefit is it having a LLC rather than just running a personal training business still suing my company name but it is not technically a legal company?

I appreciate any input. I really want to keep my company and have it grow but I am wondering if it is just a waste of $800 per year right now.