One of the most helpful things I've learned to do with ADHD is when I need to start a task, I don't think "I need to do this task" I think "I need to do (first step of task)".
I don't tell myself "I need to wash the dishes piling up in the sink." I tell myself "I need to get the scrub brush and turn on the facuet." That's easy, so I do it and bam, I've started the task.
"I need to brush my teeth" -> "I need to get my toothbrush wet and put toothpaste on it."
"I need to write this essay" -> "I need to pull up the assignment guidelines and open a word doc."
"I need to go to the store." -> "I need to put on my shoes."
Tasks are easily overwhelming when you constantly think about them in their entirety, so picking the most immediate part you need to so and only focusing/doing that helps to get you to start it with less anexity & stress.