If you are a complete beginner, I would suggest starting off with Bitcoin. Try to understand what Bitcoin is and how it works then you can dive in into more complex topics.
While reading about blockchain as a technology, you will probably encounter many technology related terms like blocks, mining, Proof of Work (PoW), Proof of Stake(PoS), smart contracts, hashing, etc. You will need a Glossary. I also recommend bitcoinwiki.org for that. You can find all the answers there
As a next step, I would suggest creating a wallet and playing with the software sending transactions back and forth. This way you get to interact with the Bitcoin blockchain. Start off with $10 USD you don't need to buy a whole Bitcoin. You will learn about addresses, backups and private keys. But here you should be very careful to choose a good wallet