Legal Question in Landlord & Tenant Law in California

Re: Breach of Contract ; Early Termination

The new lease will not (automatically) contain the terms present in the old lease - but that doesn't mean you can give 30 days' notice in the middle of the lease term.

If you sign a lease, you are promising to pay the full rent amount for the entire term of the lease.

If you move out early, the landlord is obligated to make reasonable efforts to find a new tenant. If the landlord finds a new tenant, that may reduce the amount of rent that you're liable for. However, it may take several months for the landlord to find a new tenant (if they are able to), and the new tenant may be paying a lower monthly rent than you were, so you may still be on the hook for a fair amount of money.

Re: Breach of Contract ; Early Termination

You could be responsible for the Full term of the lease. A lease is a contract for the full term, not for when one person (landklord or tenant) wants to terminate it.