Any advice for getting sleep for 8 hours?

So I’m a 31 year old male who has been struggling staying asleep without randomly waking up. I work from home and get off late around 12:45 eat. I find myself looking at my phone in bed for about an hour before trying to sleeping. Could that be the problem? Also I have started trying magnesium glyconinate 350 mg(4 capsules before bed) any advice?