Distracting thoughts during meditation is something that affects even seasoned meditators. It is a difficult thing to overcome!
In mindfulness meditation, we practice acknowledging the thoughts that arise without judgment and then recentering ourselves on the breath.
To practice this, try our meditation titled Monkey Mind, located within our Staying on Track series. This meditation was created by Tamara to specifically address this common meditation challenge.
Another meditation that helps reinforce this practice is Returning to Now. This meditation uses bells to remind the listener to come back to the breath.
Lastly, I recommend reading this article that Tamara wrote in response to this common question: https://blog.calm.com/relax/qa-with-tamara-deepening-concentration-when-faced-with-a-wandering-mind