What is the most valuable skill to learn right now?

In my opinion, it is important to begin with general understanding of the blockchain and related technologies.

I usually recommend to start with the following topics:

1. Cryptography basics - symmetric encryption, asymmetric encryption, cryptographic digital signature, hashing algorithms. It is impossible to truly understand blockchain without a basic knowledge of cryptography;
2. Bitcoin. It is the first application of the blockchain technology and very helpful for understanding its evolution;
3. Blockchain, consensus algorithms (PoW, PoS), transaction lifecycle. These are the key topics for understanding blockchain technology;
4. Smart contracts and Ethereum. Ethereum is the first blockchain supporting smart contracts. Solidity, smart contract laguage on Ethereum and other EVM chains, is easy to learn and has a lot of resources on the internet;
5. IPFS. Decentralized storage is an important component of many decentralized applications;
6. Zero Knowledge proofs. These are not easy to understand but becoming very important lately.

Once you have a good understanding of these topics it will be easier for you to navigate the world of Web3 and choose the area that you would like to learn deeper.