Get Practical Tools to Write Your Great Screenplay: https://www.practicalscreenwriting.com
Some further reading on distractions and how they impact your focus:
https://lifehacker.com/how-long-it-takes-to-get-back-on-track-after-a-distract-1720708353
https://www.inc.com/nicholas-mcgill/it-takes-23-minutes-to-recover-from-a-distraction-at-work-heres-how-to-minimize-.html