We know it sounds counter-intuitive but the first part of successfully removing your pedals is installing them correctly. The first mistake most beginners make when putting on pedals for the first time is really going to town when tightening them up. You don’t need to.
If you look at the way your pedals are threaded, you’ll notice two things: first, they’re opposite threaded, which means each pedal is tightened by turning it a different way (anticlockwise for the left pedal, clockwise for the right), and the second is that both pedals tighten the same way you turn the cranks when pedalling.
What that means is pedalling the bike actually tightens the pedals, so there’s no need to tighten them up too much when installing. I usually tighten them enough so the thread goes all the way in, and then add another gentle push to make sure they’re secure. That’s all you need.
When it comes to taking your pedals off, one big factor in how easy it’ll be is how long they’ve been installed for. If they’ve been on the bike for a long time without being removed, it can be a real struggle to get them off again so it’s a good idea to periodically remove the pedals, give them a clean, and reinstall.