Why can't I access my store admin both on app and browser?

on both the app and on browser, it will not let me access my store. it won’t let me manage my themes / website on the app and when i try to log on to browser, it tells me my password is wrong even though it isn’t. and when i try to reset it, it says it sent me an email but it doesn’t.

Do look through your Junk/Spam in your email, also do wait for a little while sometimes email traffic is high and your email might take awhile to get through the queue. Other things you want to check are that the email you are entering is spelt correctly and so is the password, make use of the show password to confirm including capitalization. If none of this works then you are best of calling or emailing shopify support.