Welcome.
When DD was around that age, I never felt that she needed to attend a preschool. We did a lot of play dates and group activities and classes with other moms and toddlers. I though that was more than enough socialization but I was fortunate enough to have the option to stay home with DD.
When DD was approaching 3 and most of her friends were starting a full-time preschool, I didn't know what the right answer was for us but at the end, we went with a part-time preschool that had an open-door policy. That program wasn't a great fit but at least I learned that academic circle time wasn't going to work for DD.
I waited until she was over 3.5 years old then she started a part-time preschool without me hanging around as a parent volunteer. It is a multiage, nature-based, non-academic play school and their curriculum is centered around teaching social skills and building a sense of community among children. It was exactly what DD needed. She went from being a bookworm to a social butterfly. She even developed a crush on a boy!
We're on a summer break and most of her time and energy go to music these days so academics have taken a backseat but she seems to be sailing right along in reading and math as well. If I were to really assess her skills, they are probably all over the map and she most likely has gaps that need to be filled but I'm not all that concerned at the moment.
I do lean towards attachment parenting and unschooling so my approach might not work for your family but it works for DD and me. We're pretty happy. Her father, on the other hand, isn't too crazy about unschooling.
