New parents tend to imagine the first dental visit as a milestone that belongs somewhere around school age, once there are enough teeth to be worth inspecting. Dentists see it the other way round. The standard advice is to bring a child along once the first teeth appear, and well before there is anything to fix, so that the first memory of the chair is boredom rather than drama.
A first visit at this age is not really an inspection. It is a rehearsal. The child sits on your lap, the dentist counts teeth with a small mirror, everyone is cheerful, and it is over in minutes. Do that a few times and the surgery becomes an ordinary place, which is the entire point: children who meet the dentist before they meet toothache tend to become adults who turn up to check-ups. The dentist also gets an early look at how teeth are coming through and, just as usefully, a chance to talk to you about brushing, bottles and sugary drinks while the advice can still shape habits.
On cost, this one is simple: NHS dental treatment for children is free. What you need is a practice with NHS capacity for children, and practices whose NHS books are closed to adults will often still take children, so it is always worth asking the question directly rather than assuming a 'not accepting' notice covers your child.
Small children take their emotional cues from you, so the preparation is mostly self-discipline. Keep the description short and dull: the dentist is going to count your teeth. Avoid the word hurt entirely, including in reassurances, since 'it won't hurt' plants the idea more firmly than silence ever could. Book a morning slot when the child is fed and fresh, expect the first visit to be brief, and treat a refusal to open wide as a rehearsal that half worked rather than a failure. Some parents book their own check-up first and let the child watch a calm adult in the chair; for a certain kind of two-year-old, that demonstration outperforms any amount of talking.
Any dentist can see children, but practices differ in how much they enjoy it. When you read listings, look for mentions of children and families, and when you ring, ask how they handle a first visit for a toddler. A practice that answers with a routine, first slot of the day, child on the parent's lap, no treatment planned, has done this many times. Among the 3,025 dental practices listed on this site you can compare family-friendly practices near you without a ring-round, and if you are weighing up private options for the family alongside, ask practices for quotes and compare from the sofa.
The appointment to book is the unremarkable one, a few weeks from now, while the teeth are new and nothing hurts. Dull first visits are what good dental childhoods are made of.