Joe
The problem is for beginners like us a mistake can set us back several years especially if you can't get your cash back out of a bad investment. I totally understand and want to follow the learn from your mistakes model but unfortunately unless you're buying £50k houses, its hard to get back into the market straight after a bad investment.
For now, I am scheduled to go to a couple of courses in January. From the sounds of it, you are right behind me in the investment journey so I'll be happy to share what (if anything) I learn from those courses and hopefully that can help