Of course you can travel by car and there are car parks available behind the dunes of both Lifeboat Road and in Victoria Road...but expect to pay for the day. For the carrkpark at Lifebaot Road it was ?2.70/car.
To reach Formby and have the freedom to walk along the coastal paths, returning from a different point of departure then leave the car at home and take the train.
We took the train from our home in West Kirby to Liverpool and changed onto the merseyrail northern line forthe ride to Formby station. If you just want to see the squirrel reserve then get off at the station after Formby, which is Freshfields, and walk down Victoria Road.