You can find a list of all supported coins at: List of supported coins
The list provides an information about what model supports the coin in question as well as any related apps to use for a given coin.
Coins that are natively supported in our app can be managed directly via Trezor Suite: http://suite.trezor.io/.
The best practice (yet ignored by some coin’s developers) is to use unique address for your coin so they don’t get mixed, in general you could say that each coin has its own address format and own wallet. For the terminology refer to: What is account/wallet/address.
Some coins are built on top of other coin’s network, ERC-20 tokens are the great example - these are built on top of ETH network, are using ETH addresses and hence can be managed inside the ETH wallet.
Few coins are supported by 3rd party wallets - these are some memorable coins with great community we didn’t manage to implement to the Trezor Suite yet (our goal is to have them all in the Suite eventually). Thanks to our partners or given coin’s community you can however protect them by using Trezor device since integration to a 3rd party wallet is possible.