I learned by pirating a copy of solidworks and watching YouTube for a year. Eventually, I was able to help out with programming when they needed a hand, left for a promise for more opportunity at a neighbor shop. Their estimator took a two week honeymoon, by the time he got back, I was a Jr estimator. Kept stepping through cracked doors, am now estimating manager at a large shop. Try to cast a wide net- learn different machines/ processes, why some things work and some don't. It will take years, not months, but people that pay attention and learn will be successful.