Get your room cool, dark, and quiet
No caffeine after morning. No alcohol in the evening. Cleanup your diet.
Quiet your mind. This isn't just an "at night" thing. In my experience people who lose sleep worrying are the same people worrying all day. Try therapy as needed.
Screen time hasn't really impacted my sleep, but I don't have any social apps on my phone, period. Listening to a podcast or reading (on the phone, with "night mode") never seemed to be an issue.
Exercise regularly, whenever works for you. Moderate/Zone 2 is a good place to start.