A) how long the password lenght it is avaiable for this time capsule
WPA uses either a passphrase (shared secret) that is comprised of 8 to 63 characters or a fixed-length of 64 Hex characters. These can include special characters and spaces.
B) how to reset the time capsule
Please review the following Apple Support article for how to reset your Time Capsule.
C) how to change the ssid
You would change the SSID, what Apple calls the Wireless Network Name, by using the AirPort Utility, as follows:
- Run the AirPort Utility.
- Select your Time Capsule, and then, select Edit.
- Select the Network tab.
- Enter the desired name (SSID) in the Wireless Network Name field.
- Select Update, and then, allow the Time Capsule to restart.