My son has ADHD. It was actually very helpful to me to get that diagnosis, and therefore know to read up on parenting advice for how to parent a kid with ADHD. I don't know if you kid has that or not, but most of the distractibility and impulsiveness can be lessened through teaching certain tricks and tips to manage it.
Mostly, it made me see multiple reminders are OK. Not are they only OK, they are often necessary. I mean, I put so many reminders into my phone these days, it's crazy. I could manage my own life as a single person, but have always had trouble managing mine, my husband's, and my kids, without some sort of calendar that I record things in faithfully. You might have to be the reminder for awhile until your kid can write things down in calendars or get an app on an ipad or something.
Things that help and cannot hurt:
1. ensuring a regular schedule, wake times, eating times, sleep times, etc.
2. eat healthy, balanced food on a regular schedule. Keep the blood sugar levels consistent. No empty snacks.
3. exercise is key. outdoor time is critical, IMO. Get that kid out for a hike in the woods, a bike ride through a park, a basketball game, etc. Ideally, several times a day for exercise breaks.
4. Fish oil pills can help. Check with doctor first.
For more targeted help, building off the schedule helps my kid. Mine is older, 11. He wants to go play outside after dinner, but if he does, he gets too distracted and will not come back inside in time to do homework. So while another kid might be able to handle flexibility for warm spring evenings, my kid can't. Homework is always after dinner, no matter what. Checking his backpack in the morning to ensure he has everything he needs is a must, no matter what.
He has issues completing his shower and toothbrushing routine at night. He wants to shoot nerf baskets, do somersaults, go hug Daddy a million times, play with a toy, etc. I had to get a large timer clock to sit in the bathroom as a visual reminder that he only has a certain amount of time to get ready for bed.
During conversations, you can prompt him to return to a particular subject. And his teachers should be doing that anyway.
This website for ADHD has a lot of great advice of lifestyle tips and tricks to deal with the symptoms of ADHD. Again, your child may not have it. But many of these approaches could be helpful.
https://www.additudemag.com/manage-your-distractions/