How to learn blockchain technology

First, build a foundation by understanding concepts such as the general theory of electronic cash systems and distributed systems. Then develop some understanding of cryptography. This base will provide you with a basic knowledge of the technologies used in blockchains. 

After this, you can pick up a Blockchain platform, e.g. Ethereum or Hyperledger and read the relevant research papers. 

Also, start experimenting with building test Blockchain networks and writing small smart contracts. Once you have the necessary understanding try to build a complete end to end project with a user interface, smart contracts and implementation on a Blockchain network, either public or private. Many enthusiasts are coming to understand and work on this technology from various fields, who may not have a background in computer science or web development. Therefore it's important to focus on the basics first and avoid using any third party frameworks or development tools in the first instance. When you have understood the theory and fundamentals then you can start using various frameworks and tools which will make development and deployment of smart contracts, and decentralisation applications (DAPPS) easier. for example truffle, ganache and drizzle.