Tbh I don't think the course could lead to self-employment as an accountant. I don't even think it could lead to self-employment as a bookkeeper, as it teaches you to use a specific piece of software rather than the fundamentals of bookkeeping itself, which you really do need to understand in order to do the job.
As an accountant, the thing that clients are interested in is tax, how much they have to pay and how to minimise that. You couldn't offer any of those services and there is a reason that accountants train for many years and have rigorous continuous training.
When I started my accountancy training the first thing we did was spend two full weeks, so over 70hrs on a basic bookkeeping course before we could go out on the job as trainees at the start of our 3 yr training. The course you are talking about is 20hrs and is software based.
With regard to bookkeeping, you could set up but there are also qualifications and institutions for bookkeepers and you would be advised to consider those.
What the sage course may well help with is getting an accounts clerk role in an organisation. I think that is it really.
Sorry if I have rained on your parade but a cheapie groupon course is just not going to give you the experience or knowledge to be able to trade as an 'accountant' competently.