Call the City of Austin at 512-494-9400 and push the appropriate number for
solid waste services 
, or dial 311. Delivery of trash receptacles is not automatic when you set up your electric service. Call a few days in advance of when you'd like service to commence and they'll drop off your containers the next trash pick-up date (for my street, at least, it's Fridays). They did warn me that it may take up to two weeks, so we plan to have ours delivered the Friday before we close, rather than the Friday after, just in case it does take extra time.