You best route for becoming a blockhain developer is to take an online course.

It's possible to learn about blockchain using Python. Most of the blockchain tutorials for python I've seen are geared towards beginners so I'd recommend you take one of those first.

https://youtube.com/watch?v=pZSegEXtgAE
https://www.tutorialspoint.com/python_blockchain/index.htm
https://developer.ibm.com/technologies/blockchain/tutorials/develop-a-blockchain-application-from-scratch-in-python/
https://www.codecademy.com/learn/introduction-to-blockchain
https://www.udemy.com/course/build-your-own-cryptocurrency-in-48-hours/

I assume you don't know Javascript so I think you should avoid blockchain NodeJS tutorials unless you're looking to get hired by big companies using Hyperledger Fabric (a buzzword), then you should learn Javascript as it only has an SDK for that and Go. If not, you're good to go. There aren't a lot of blockchain tutorials for Java so I'd avoid that completely.

I should emphasise, Python is mainly used for trivial blockchain applications. Large projects like Bitcoin, Litecoin and other big cryptos are written in C++ because it's faster than Python. But these are community projects so you're unlikely to find employers for C++, except for Blockstream, Chainalysis, the various exchanges, and other companies I can't remember off the top of my head.

So use Python only for learning purposes, you only need to know Python basics to understand what the Python blockchain courses are doing. Serious companies will use either C++ or Javascript.

When you finish with all that you should study the Bitcoin developer documentation https://developer.bitcoin.org/, it will give you an idea of what a production blockchain is supposed to have.