Encrypting a 64-bit binary number to a text containing upper- and lowercase, and digits I am making a tool that generates 16 character long password out of a 64-bit binary number. But I dont know how to make an encryption key for that, or where I can find one.

To show what i mean, here is an example with 8 bits:

I have the binary number: 10110111

The output could than look something like this:

t6Yli12q 

And I want the password that gets generated from this: 10010000, to be completely differnt than the password that gets generated from this: 10010001.

Can anyone help me with this, or maybe redirect me to a site that says something about these types of encryption?

Note: I am very new to cryptography, so this might be simple for most of you, or maybe harder than I think.
You can use Key Derivation functions (KDF) to generate secret keys, e.g., from passwords. In 2013 a Password Hashing Competition was organized and the winner is Argon2 KDF. Argon now very popular and it has a new version named argon2i.

From Wikipedia;


  In cryptography, a key derivation function (KDF) derives one or more secret keys from a secret value such as a master key, a password, or a passphrase using a pseudorandom function. KDFs can be used to stretch keys into longer keys or to obtain keys of a required format, such as converting a group element that is the result of a Diffie–Hellman key exchange into a symmetric key for use with AES.


Once a key is generated, you can stip the key into the desired size.

In the end, if you want to human readable generated keys apply Base64 encoding for the derived key. Base64 encoding uses 6-bit to encode data From $A–Z, a–z,0–9$, and $+,/$.