What bitbollo said, but also pay attention to the following:

1. don't delete the existing wallet even if you don't remember the password. Just ignore it and create a new one.
2. try to remember if the existing wallet was sent to anyone who could potentially pay you. If so, you need to keep trying to remember the password.
3. don't send funds to the existing wallet. I guess, since you don't remember the password that you can't open it to copy a receiving address anyway.
4. copy the seed phrase of the new wallet. I suggest two copies stored on paper in different secure places.