Fairly sure it doesn't lock out after a certain number of tries...
You can always just make multiple backups of the wallet file before you attempt to try different passwords, just in case
Without the password, there is really no way to regain access to your coins. So, you will have to try "cracking" the password using something like btcrecover or maybe get in contact with Dave at
walletrecoveryservices.comOther options are "John the Ripper" or hashcat... Although I'm not sure if they're compatible with MultiBit Classic... I've never tried either.