Giving yourself time to disconnect from the day is crucial. I give myself 1 to half an hour because it takes my body that long to get in the mood to be tired. That means nothing stimulating. Work is off the table, and no tech as much as it's feasible. Any activities before bedtime should all be relaxing. Having an evening ritual helps. I signal my body for sleepy time by changing all lights to dim warm lighting, including my handphone, and cooling the room down. Then I make a bedtime drink e.g. warm milk or non-caffienated tea while doing said light activity e.g. reading, chatting with friends, meditating, prepping for the next morning, reflection etc. until I drink finish. I brush my teeth and do my toilet business after that. By the time I return to bed, lights off and I put on aromatherapy or some meditative sleep music and drift off.
To become tired earlier you should try not to eat 1 hour before you go to bed. You also should try to stay away from your electronics an 1 before bed. You may have to change your schedule though, if you’re wanting to sleep earlier.
During the day and evening try to make sure everything you're doing is meaningful; either being productive or enjoying a hobby. Focus on not wasting time and procrastinating to the night. Then at night focus on what you can do the mext day to be productive, rather than thinking about what else you can do that night.
Start putting an alarm or reminder to go to bed at a a certain time. Also try to loosely schedule your evening so you know when you'll sleep. Even if you're not tired, get ready for bed and then read or meditate or third option.
Also set your alarm(s) and make sure to get up at that time without sleeping in