A strong password is long, unpredictable, and used for one account only. A short string with symbols is not automatically safer than a much longer random password.
Use a password manager to generate and store a distinct password for each site. Avoid names, dates, keyboard paths, and phrases that others could connect to you. If a service supports passkeys or multifactor authentication, enable them as additional protection.
You can experiment with Akousa's password generator, but do not paste an actual account password into a checker unless you have verified how and where that tool processes input. If a password was reused or exposed in a breach, replace it even if a meter calls it strong.