As a verb:
* The loud music sidetracked me from my work. (Meaning: the music distracted me and made me stop working)
* Don't let the gossip sidetrack you from your goals. (Meaning: don't let unimportant things distract you from what you want to achieve)
* We tried to stay on schedule, but the unexpected meeting sidetracked us. (Meaning: the meeting changed our plans and made us fall behind)
As a noun:
* The conversation took a sidetrack into childhood memories. (Meaning: the conversation changed direction and focused on something different)
* The new project was a sidetrack from our main priorities. (Meaning: the project was not part of the main plan and took time away from other important things)
Other uses:
* I'm afraid this is just a sidetrack, the main issue is still unresolved. (Meaning: this is a minor point that is not the main problem)
* We're on the right track, just a slight sidetrack to consider. (Meaning: we're mostly on the right path, but need to briefly focus on something else)