A strong foundation in at least one object-oriented programming Language is key. Popular choices are: C++ JavaScript Python Solidity
Grasping the fundamentals is vital , Learn Distributed System Consensus Mechanism Types of Blockchain
To Efficiently organize and storing data on a blockchain, Learn Linked List Merkle Tree Hash Table
For The pillar of blockchain security, learn Hashing Function Digital Signature Public/Private Key Cryptography
Databases and Networking Web Development Basic Cryptography and Security Principles