Switch straight to underwear.
You want your child to feel the wet sensation when they urinate in their underwear. This is building their awareness.
Most importantly, you don’t want them to sit in a soiled diaper since they get used to the feeling.
You want them to notice right away and change them. They will learn the difference between wet and dry.
I don’t recommend pull-ups since it is essentially the same thing as a diaper. You can use training underwear (thicker underwear) or plastic pants (avoids the mess, but the child still feels the wet sensation).
Underwear is great because they are inexpensive and reusable.
Children also feel good wearing them since it is more like what big kids wear. This helps give them the boost they need to feel excited about toilet training. Some kids like to be involved in the process of choosing their underwear. They like to choose cool character underwear.
If you don’t want to train at night, it’s ok to stay with pull-ups. But change them the second they wake up and put it up right before bed.
This is tip is based on Toilet Training in Less than a Day. It’s an old book but it has endured and is still considered the most research-supported intervention.