The only real mistake is the one from which we learn nothing. - John Powell
It is okay to make mistakes. If you accept your mistakes, you learn from it. You're a teacher. You tell your students the same thing, right? You tell them that they're learning from their mistakes. Practice what you preach. And remember, you're awesome because you have taken the second most difficult job in the world - being a teacher.
USE the internet, there are plethora of information for you to learn from, lessons plans developed by other teachers to give you ideas, pintrests for people who likes to be creative and share their creativity, and common core standards that you can use and apply in your fun-filled instructions.