I am a "Veterinary technician" as a pre-vet student. I worked at a general practice (for wildlife/avian/exotic/small animal patients) and all during high school I cleaned cages, and gradually learned enough to become a technician. In the general practice, this is basically taking TPR's, minor phlebotomy skills, history taking, and the ability to advise clients over the phone/on husbandry of their animal/how to administer meds/etc.
When I came to UNH, I applied at the emergency centers nearby and got a job as a tech assistant at a large practice for small animals. It's amazing. However, the knowledge I had at the other place is nowhere near enough to be a technician at this emergency center, nor would I want that responsibility. I do not have the knowledge yet to suffice as a technician (although I can place IV catheters and have minor phlebotomy skills from the general practice). I feel as though I'm not always 100 percent sure of the why behind everything. Almost like I am simply going through the motions of being a technician. I always ask about everything though, and will say when I don't know. Because, well, I don't.
Basically, any entry level position will get you what you need for vet school. No, you do not have to be a veterinary technician.
I wouldn't insult the veterinary technicians (LVT's, RVT's, CRT's) and say that I am at all knowledgable to act as a certified technician. I did not go through the schooling for it. However, I've seen some people become absolutely amazing technicians without the schooling, and after being in practice for several years.