You will be living in Mexico, so you should have at least some pesos in your wallet when you arrive.  If you let most NOB banks know well enough in advance, most will exchange your dollars for you so you can have those pesos in your wallet well before you enter Mexico.

• Get more (I recommend three times) the amount of Mexican pesos than you think you’ll need for tolls and unexpected expenses (see below) from your bank and have your pesos ready to go.