Thanks for the question.
At the 18 to 30 months stage of development most toddlers do not play together. They will play next to each other and my take an interest in another child but often will not share toys or even communicate with each other, so making friends (as adults understand it) may be difficult.
However it is good for children to be able to socialise and get used to other children for the future. If your child is a bit shy then a whole group of other children may be too much, overwhelming, so why not start with a simple play date with one other child of a similar age. Make sure you start by sitting with them until they get familiar with the each other, you can then gradually move away but stay within sight . At this age children need to know where you are still there to be able to explore and interact with others.
Try and set something up on a regular basis and once a child gets use to interacting with one child you can try a small group event. Ideally somewhere they are familiar with, bear in mind to start with they may spend the whole time on your lap. Keep with it and when your toddler is ready they will gradually move away from you and start interacting with others. Eventually they will find a child they like an become friends.
Jill Wheatcroft is a Lecturer in Child Health and is co-founder and Director of Training at Riverside Cares. She can be contacted at firstname.lastname@example.org://ww.riversidecares.co.uk