How do you find out what ur username and password is for Chase bank?

call the bank only they will have this information

you are the one who makes it

Well, first you have to have set up such a thing.  You don't just automatically have one.  You have to have gone to a Chase bank at least once to set it up.  I make no accusations, but if you are trying to get into someone else's account, you won't know enough of the required information and it would be a lost cause.

If you have a legit account but have forgotten your username and password, go to the www.chase.com web site and click on "I forgot my username."  The web page will ask you for your e-mail address and IF that e-mail matches an account on record, they will send an e-mail there containing a web link to let you re-enter that account. 

If you can't supply the correct e-mail, or even if what you can supply does not match their records, they won't help you over the internet.  If you cannot give some other information that uniquely identifies the account, like the answers to the security questions, you won't get anywhere over the phone either.  If that happens, you will have to physically go to the nearest Chase bank and be prepared to show some ID to a bank officer.  They would be able to help you then.

Note that even if you know the username, password, and security questions and answers, if you change computers you will get pinged because they keep track of the system from which you usually access your account.  When I lost my hard drive a while back, the replacement looked like a new machine even though everything else about the computer was valid.

I've been with Chase for 20+ years.  They are pretty secure in the way they handle web logins and account information verification.

if you've forgotten it, talk to Chase.  if you haven't registered, go to their webpage and set up an account.

If you have never made an online account with your bank, you should be able to create one. They'll ask for some information to verify your identity, and you should be able to create your account. Otherwise, if you do have an online account, but don't remember your login details, you can always reset them.

How do you not know your username and password?

You look where you recorded that information for future reference.