New OutDoord GROWER W/ Picss

Hi everyone I am new to growing I started these plants outside and was wondering how do I tell which one is male an female> I also have a picture of one plant that split into 3 stems what is up with that? Also the white stuff isn;t mildew its a powder to keep bugs away..
Please offer any other helpful advice...

You're too early. You'll be waiting for a month or two yet before you see a sign. Expect to harvest around sept/oct