option 1: a brainwallet: we calculate sha256 hash of text. the result is 64 byte hexadecimal number. in fact result of calculation of hsa256 of any text with any length always is a 64 byte hex. then in this option the length of text is not necessary be 32 character.
that is not the only way! there are literary hundreds of methods to use for brainwallet because there is no standard for it. for example you can perform multiple rounds of SHA256 on it. or this "password" you use can be the password of a PBKD2 with some iteration count and then derive a 32 byte result from it.