https://guggero.github.io/cryptography-toolkit/#!/hd-wallet

☝️ Fantastic tool. I used it a lot when I was writing tools to do these key derivations (just to confirm I fully understand the process). That'll let you do everything except use a xpub to generate more addresses.

A quick search turns up https://github.com/swan-bitcoin/xpub-tool to do that.

Use these tools to understand the concepts and then you'll be all set to implement it in your language of choice (or better yet, find a library that has already done so).