I'd rather learn by myself and watch some videos online tbh. The only advantage of someone mentoring others in gambling is their personal experience and tbh, even with the tips and tricks behind it, the experience would still be the king in telling if someone is learned in the way of gambling or not. Besides, with you learning by yourself, you'd be able to spot anything that is unpleasant and unneeded in your eyes, plus, it could perfectly fit with your budget, time and other factors involved. Learning by yourself number one!
Right, then you should also apply what you have learned so you will know if its gonna work and effective. Well, I agree on what they have said to you OP, there's a lot of tutorials and guidelines in the internet to learn and master poker, no need to buy those; just a waste of money. And for sure, the thing/s you've bought are just from free and public sources. But I doubt you, I think you didn't purchase it, you just want to sell that materials to earn some bucks gotten for free.