Create your wallet and save the file and equate it in an on-site location, but the metamask is also a security-relevant way
The simplest way to store your bitcoin is to create bitcoin wallet and put it a safe place. Furthermore, if you want to make it secure you should not share your password and private key to anybody so that you can assure that your bitcoin is safe and secure. You can also put authenticator so that you could know if someone want to open your wallet.