Transfer Student Help!

Hello! I am a middle class female at a small (non competitive) liberal arts college currently planning to transfer colleges, probably in fall 2018 as I hear it is better to transfer in the fall. I am planning on transferring to a small liberal arts college like Wesleyan, Vassar, Smith, Wellesley, ect.
So far, I am doing well in classes and aiming for a 4.0 GPA. I am in Young Dems, a feminism club, Crew, Catholic Student Association, and an environmental club. I am planning on majoring in Biology or Political Science. When should I begin applying? How likely am I to get adequate financial aid? Which schools would be most likely to accept me and give me aid? Do you have any advice?
Stats- (HS)
ACT- 34
GPA- 4.67
AP- 13 classes

Also, I feel like I should add I’m not quite sure of my major- will that make a difference? Also I’m looking for a more rigorous academic environment and a more liberal political atmosphere, if you have any suggestions. Thanks!