I would look carefully at maps to find a route that avoids higher speed roads if at all possible. The rule of thumb that I've given my kids is to avoid roads that have two or more lanes of traffic going in one direction, because the drivers are being controlled by the flow of traffic rather than vice versa. Unless there is a dedicated bike lane.

Once you gain a bit more confidence on the neighborhood streets, you will be a better judge of which of the faster roads you can ride on.

See if cyclists have already found a preferred route through your neighborhood. I live on such a route, and dozens of bikes go by every morning. There's strength in numbers, and the car drivers expect us.