General private/public key generation Not sure if this is the correct forum to ask, but I couldn't find a general one for all cryptocurrencies
I wanted to get an idea on how the whole cold-storage private/public key generation works for different cryptocurrencies. So I was playing around with BIP32 deriviation path on: https://iancoleman.io/bip39/#english

I noticed that for example BTC, XRP, PIRL all have the same BIP32 root key and BIP32 extended private/public key, but DOGE was completely different. Why is that? BTC hashing algorithm is SHA256 and PIRL uses Scrypt, their root seeds are the same, while DOGE which uses Dagger has a different seed and private/public key.

The second part that I don't understand is the generation process of addresses for different cryptocurrencies, is there a web site where I could look up on how it's done? The only one I found is for bitcoin here https://www.mobilefish.com/services/cryptocurrency/cryptocurrency.html#refMethod2
I can't say I'm familiar with all of the cryptocurrencies you mentioned, but the Bitcoin clones generally use elliptic curve (secp256k1) cryptography and the same address generation scheme.

Keys

A private key is any 256 bit number. However, for the EC used by Bitcoin, it must be between 0x1 and 0xFFFF FFFF FFFF FFFF FFFF FFFF FFFF FFFE BAAE DCE6 AF48 A03B BFD2 5E8C D036 4140. Any random number in that range is valid.

A public key is calculated from the private key using the elliptic curve algorithm with the secp256k1 parameters, which is a one-way deterministic algorithm.

BIP32 is a standard Bitcoin proposed for key generation so a hierarchy of keys can be derived using a set of indices. This is to be implemented by wallet software to make it easier to generate a set of keys deterministically and restore them if needed from a single master key and set of indices. It is not required to follow BIP32 to generate a valid key pair.

Addresses

See Address, Technical background of version 1 Bitcoin addresses, and List of address prefixes.

Also, I wrote this article explaining Bitcoin address generation step by step, which might be helpful: https://medium.com/coinmonks/how-to-generate-a-bitcoin-address-step-by-step-9d7fcbf1ad0b