for example i wont o open an trust wallet but they offer only 12 seed phrase how to use 24 word ?
As already said, a 12 word seed phrase provides 128 bits of entropy and is secure enough.
If you really worry about your security, you shouldn't use trustwallet at all.
Trustwallet is close source and there is no way to know how the keys are generated and whether they have access to the keys or not.
There are many wallets that are better than trustwallet.
A good option is electrum. It's available on Linux, Windows, Android and MacOS.
The desktop version of electrum allow you to generate a 24 word seed phrase through command line in its console. Just note that electrum's seed phrase is not BIP39 and it can be imported only in itself and bluewallet.
If you are on dekstop, you can also use Sparrow. Sparrow allow you to generate a 24 word BIP39 seed phrase easily.
If you are on mobile, you can also use bluewallet and Samourai. Of course, none of these wallets generate 24 word seed phrase.