'Strange' means something unusual in a way that you can't understand. They're sometimes used to show slight disapproval or distrust, However, 'weird' means something informal very strange and unusual, and difficult to understand or explain.
For example:
This is a weird situation, I don't kmow how to explaing you how it happened.
This dress is strange, I didn’t like, so it doesn't have my approval.
Hope you have understood.