We are dwarfs standing on the shoulders of giants.
You really don't need to reinvent the whole thing and build your own machine, and then teach yourself to fly it.
Use the experience of those around you, and you will save yourself a lot of time and money.
If you invest your own time and money into constructing a machine, then bend it on the first attempt at flight, even if you come off uninjured the whole exercise is still a waste.
Another vote here for gliding as cheap but quality way to get airborne, and you'll meet some fantastic people along the way. Club atmosphere is great, and even when the weather is pants it's still a good day out. When you do then get to solo stage, it's all the more satisfying to look back at your accomplishments rather than to hurl yourself into the air untrained as a test pilot with no experience.