I'd not do a course because I can get as far as possible with the free sites. To prove anything costs money - and that's out of the question for me.
There's no point, to me, in learning that you need to get XYZ .... and if you spend £££ on this membership and that membership then you get more records .... and if you travel 300 miles and stay a week in a hotel you can paw through XYZ resources in the archives.
It's an expensive hobby that draws you in .... just one more cert .... if I only had that cert .... that membership gives me so much more .... just a 3-day break in XYZ town with hotels/transport/dinners .....
And with every step, every discovery, you simply add more research, another 10 people and potentially another 100 bits of expensive evidence and proof to add


So, doing a course is the thin end of the wedge.