You may need to check with several locations. Every location is looking for something different. Make sure that you are talking to the Practice Manager and you are letting them know that you are also interested in a position once your externship is done (they don't want to put time into training you if you plan on using that training somewhere else ). You may also need to check with your state's regulations as to what you can do legally. I know that in AZ, it was much easier to use Vet Tech students in our hospitals because the AZ laws were not very strict. My staff consisted of approximately 13 VAs and only one CVT because I just had no need for CVTs. I am now in Oregon and the law requires certification for only a few tasks but on the other end of the spectrum, I know that in Nevada and they require that you be certified to even do dental cleanings. It is all variable.
Stay positive, confident, and don't sell yourself short. You will get there.