I received a T4A and Releve 1 form. Does this mean I am self-employed?

If so, what boxes should I check in "Your self-employment profile for 2016"?
Also, I don't know what to answer to the question "Do you have self-employment income?"

Then in the Errors section, they ask me for an industry code and they said that I have entered an invalid one. I haven't even entered an industry code anywhere. I don't know how to resolve the error.

They also ask for a business address. I don't have a business address - I don't operate a business.

They also ask me for a description of the product or service offered. I played the organ one time at a funeral in 2016, that's all. I don't operate a business.