Find a routine that you are comfortable with before you serve the pickleball. This pre-serve routine could be bouncing the pickleball with your hand or hitting the pickleball a few times with your paddle—whatever you feel comfortable with. This will help you tell your mind and body you are ready and also help you with your timing on your serve.
And, whatever your pre-serve routine is, be sure to say the score before you start any part of your serve. In other words, do not say the score and serve at the same time. Too many errors happen if you do both simultaneously. So, think, say the score, do your pre-serve routine, and then serve.