That's not so difficult, the internet gives us every tool we need. I' don't know C ++, but i found some basics how to in javascript (it s simpler, trust me):
https://github.com/ltearno/blockchain-js
https://medium.com/@lhartikk/a-blockchain-in-200-lines-of-code-963cc1cc0e54
https://www.savjee.be/2017/07/Writing-tiny-blockchain-in-JavaScript/

Just do it, again and again. Ah you probably need a little of technical background, so i suggest you to read and study Mastering Bitcoin by Antonopoulos.
Finally blockchains may have different consensus protocols. Bitcoin foresees a proof of work concept (computing power to ensure randomness in forging) Ether eum uses PoS, Lisk DPoS and so on.. try to figure all of it out!
Good Luck!