Stone masons say that all you need to be a stone mason is a weak mind and a strong back. It's true. Stone masonry is not rocket science. There are a few basic rules to follow and the rest is just hard labor. I bought a thin, paperback How-To book, I think it might have been a Sunset Guide out of California and then build a 10 meter retaining wall. Took a long time but it turned out beautifully.

Follow that dream. My mother always wanted a greenhouse and to raise chrysanthemums. I offered to build her one but she said that it would cost too much, even though she had plenty of money. And then she died. She never had her greenhouse. I've taken that lesson to heart. Don't wait. Go for it. Best of luck.