Buying a car seat for your baby or toddler can be a worry. You may not have a lot to spend but certainly do not want to skimp on safety and quality. The advice is to never buy a second hand car seat unless you know it has been looked after and not been involved in a car accident, so ideally only from family or close friends.
There are many different types of car seats available and knowing which one to get can be tricky. When the child is newborn, they need to be in a rearward facing seat, this can be either Isofix or using the car seat belt. Once the child is old enough (although actually weight of the child is more important than age as children vary in sizes when at the same age) you can move them in to a harnessed front facing seat and eventually in to one that uses the seat belt rather than a harness. Car seats are put in to groups such as 0,1,2,3 and these groups tell you how the seat can be configured. Many group one seats can also be turned in to group 2 and 3.