In Canada (and the States I think) you can run a small business under your own legal name and you don’t have to register it. If you were running a dog grooming business or something, you’d need a formal “business license” but even with a home-based business you may still need one, but it’s unlikely and it’d depend on your city’s policy. Even if required, I’m sure many people unknowingly skip this step and life goes on!
As for spelling and grammar, I’m not the best writer either! I make a ton of spelling errors (probably in this post too!). I use Grammarly and I have a proofreader (my hubby!) so as long as you use an editing app or have someone look over your writing you should be fine. And the act of writing every day will help improve your writing skill! Good luck!
These little jobs are done by people who log on to a company’s site and choose tasks, which could be as simple as clicking a link. Amazon's Mechanical Turk is one of the most well-known sites of this type. Also, there are crowdsourcing projects, which are similar to data entry, where companies engage an army of virtual workers to each do one small part of a larger project.