1. Don't try to become an expert in all of the topics the first year. Pick one unit to really hone in on and do an amazing job with that unit.
2. If you teach in a school with several teachers at your grade level, try trading students for each unit so that you can teach the same unit to each class, while your colleagues teach specific units to yours.
3. Do as much background/content research as possible. Teaching a new unit that you are not familiar with can be intimidating. Use the Internet to find sources to help you build background. There are many excellent videos and websites out there.
4. Enlist the help of your PTA or other school sources to help you purchase the required materials to give your students hands on experiences with the content.
5. Look for workshops offered by your school district. Many districts offer courses or workshops for free.
Finding some good resources to help you teach the NGSS is also important. Unfortunately when districts adopt new standards, there's often lag time before resources are purchased to support teachers. Check out these entire year bundles available in my store:
Enjoy your year of Science!
