You can reset your password by going to Settings > Setup > Users and click 'Reset Password' beside the user you wish to reset. You can see this is highlighted in the below image.
Once you click on this, the screen below pops up advising that an email will be sent to the email address against the user record. The email address has been redacted out in the image below
To receive this email you click 'Reset Password'.
The email you will receive looks like the one in the image below. You click on the link and this lets you reset your password. The link in the image below has been redacted.