First off, how do you even find out about these coins?
Second, what exchanges can you even find these coins? It seems almost all these altcoins are related to ETH. Does it involved pancakeswap/metamask and things like that? Is it easy to learn?
Third, these coins don't have any correlation to btc?
You can check coins, their groups and announcements usually if those coins have interesting updates or achieve a milestone the price could go up even all the coins are down. Altcoins are usually coins that is not Bitcoin so any other coins whether it is from ETH, SOL, MATC or any network it is considered as an altcoin.
No, the only correlation I see is when that coin can be exchanged to BTC like ETH/BTC, SOL/BTC, etc.