Engineering is logic. Not everyone can be an engineer, like not everyone can be a good tradesperson. First of all, do you have that way of thinking ?

If you think you do, and your serious, then save your money and start buying tools. Buy hand tools, air tools, battery and power tools, a mill, a lathe, a mig, an oxy torch, ect. Then start working. You learn by doing. If you have success, gain experience, theres no need for any formal qualifications, you only need the skill. Go and show them what you can do, and you'l be hired.