Hello!
According to the guidelines posted here re: what "cultural activities" means, you should qualify for the Self-Employed Persons class since video camera operator falls under "Technical support and other jobs in motion pictures."
https://www.cic.gc.ca/english/helpcentre/answer.asp?qnum=291&top=6
You don't need a business plan to apply, but you do need to provide a "narrative document" that tells how your experience as a video camera operator has financially supported you and/or your dependents for at least two out of the past five years. You should be able to show that your experience as a video camera operator will be enough to sustain you and any dependents after you move to Canada without your needing to apply for other jobs that would otherwise go to Canadian citizens.
You do not have to have an immigration lawyer to apply. I applied without one (currently waiting for my application to be processed.) I found it simple enough to do as long as I followed all the instructions very carefully. The immigration.ca web site has a lot of problems and many of the required forms would download as blanks, etc., so I had to put a lot of effort into getting all the forms I needed and as a consequence it took longer than it really needed to. So an immigration lawyer can probably move through this process much more quickly for you... but it is entirely possible to go through the process on your own. The instructions are clear and easy to follow; it's only getting the correct forms that is difficult!