Try using the teacher face/voice. You can practice the face in the mirror. Unfortunately, family members can be a bit harder to control, but if you are consistent and firm, they'll come around.
Volunteering is a great way to get experience, so you should definitely include it! I usually charge about $12-$15, depdending on the job and whether the family is asking for extra things like cleaning. Most families are able to afford that range.
The toddler class in a preschool is typically 1-year-olds. 2-year-olds are usually considered toddlers as well. By 3, they are not "toddling" around, they are able to run and jump and are MUCH more coordinated than what I would consider to be a toddler.