Planned my day and I’m already behind

I created my ideal plan for this week and also one for today. It’s only 8:30 and I’m already behind. How do I manage my thoughts around this? Do I skip ahead in my schedule and work on what’s scheduled for the current time? Or do I just push through with my original plan and feel behind all day? I’m assuming over time I’ll get better at knowing how long things take and hopefully working faster. Any tips for that?