If you are concerned that your child may have a potential delay in any area of development, the best approach would be to discuss these concerns with your child's pediatrician. The best evaluation done on your child would be done by a developmental pediatrician or a psychologist who does psycho-educational evaluations. These are evaluations that are specific to a child's development. They look at all areas of development, cognitive, social and emotional. They look at language and communication, gross motor and fine motor skills. This gives you a framework of where your child is within each domain and whether or not a specific intervention is needed or a further evaluation within that domain, to further assess their skills.
For example, if you take your child to a developmental pediatrician and they come back to you and they say, "In the area of gross motor skills, your child seems to have a delay or difficulty with running, with climbing, and I would recommend that you see a licensed physical therapist to further assess your child's gross motors skills." After seeing the physical therapist, the physical therapist may suggest that your child come in for therapy to address those specific delays. Again, the best way to start is to discuss your concerns with your child's pediatrician and to then possibly get a complete evaluation done by a developmental pediatrician or a licensed psychologist.