Question about making your Solana wallet safer.

So I use Phantom, and I wanted to make a 24 word seed phrase to make my money be kept safer and the only way I managed to make this work was through a BIP-39 24 word generator, I entered the words gave to me through the generator and it did work out to create a 24 wallet word on phantom, but I wanted to ask is this safe? I used a BIP-39 generator to generate my wallet, what are the chances someone is going to access this wallet I generated? Can I move my money to this new wallet? Is there any other safer ways to create a 24 word wallet? Are 12 words really enough? What should I do?