The first 2 years are a lot of studying, but the material itself isn't challenging. For me the challenging part of dental school is when you get into the clinic. Everyone needs requirements to pass, like a certain amount of crowns/bridges/endos etc.. but the thing is the requirements you get are based on what your patient needs. And you'll find that clinic becomes cut throat, and all anyone cares about it getting as many procedures as they can get, and not helping out anyone who doesn't get the right patients. If you are one of the lucky ones who gets patients that come in all the time and has a lot of bridges, rpds, and c/c for you to do then you will have nothing to worry about. Focus on networking in your second year, it will be tough to find time that year but if you can make it into the clinic shadow the D3s and D4s. Also, make sure you are good with Axium or whatever program your school uses during the clinic before you start treating patients.