Baby pacifiers are almost an essential part of caring for a baby. Not every baby needs or wants them, and it's better if you could do without one, but for those that do (which is most) it's almost indespensible, and it's definitely better for your baby than sucking on a thumb.
The ones that you want to find are
orthodontic pacifiers, which means that they have a better shape and are better for your baby's oral health. The pacifier guard should be quite large and prevent your baby from putting the whole thing in the mouth, which would be a choking hazard. Many babies can be particular about which
pacifiers they like, but once you find a design or brand that your baby likes it's usually advisable to get quite a few of them, since they're very easily lost and misplaced.
To try to reduce the possibility of dropping or being lost, there are also some very cute
pacifier holders that will clip onto your baby's clothes. So when you're looking away and baby decides to spit out the pacifier, you won't have to worry about it falling to the ground or being completely impossible to find when you need to get to it again!