Is the 1st Encrypted Block Less Secure Than Subsequent Ones?
In the first block, the IV provides the "randomness", and in subsequent blocks you just use the previous block of ciphertext instead. Based on the assumption, that the cipher is not weak and behaves like a pseudorandom permutation, this is basically the same: You XOR something unpredictable on the plaintext, and then encrypt.

As long as the IV is chosen randomly (and therefore, it should never be the same), there is no weak beginning. If you disregard the randomness and always start with the same value for a new message, then yes, the first block can be considered weaker. Because then you can distinguish, if two messages have the same beginning.