It solely depends on the objective of the Blockchain that you want to start working upon. Also, it depends on if you want to have an open or a private Blockchain. If you want to start up a private Blockchain where access to the Blockchain is controlled and the data isn't open, I suggest you start reading about Hyperledger Fabric. On the other hand, if you want to start up a public Blockchain, which is when everyone would have access to the Blockchain and then it would be open.