Here is My request, If we have request to create login on one server in PROD environment, That Login should be created on all other instnaces By creating on one server.
If possible avoid creating sql logins, instead use windows login which will get authenticated on AD. If you use windows id then half of your work is already finished.
Now coming to your second question,
Second question is when we create login we will give default password, so when user try to login 1st time the user should be prompted to change password. Can someone help this by doing with script?
Again same answer, create windows account instead of SQL. The account will be created in AD and the required setting you can configure there.