Ok so my daughter is going to be 3 years old this year and seen her dad when she was 2 months,4 months,8 months and 9 months old but that's it.ive been with my current boyfriend since my daughter was 7 months old and he's been her father ever since then and her real dad never comes around.she don't know who he is.im getting married this year and my fiancé wants to adopt her.I don't know where my daughters real father even is. I don't have his number and haven't talked to him in almost 2 years. Would I need his permission for my fiancée to adopt my daughter?

Yes, normally they will need his permission and you will have to show attempts to find him to get that permission, Have you contacted his family ?
Is there a child custody order in place ( if not why)
Is there a child support order in place ?( if not why)

You well need to at least show a good faith attempt to contact him for his permission. You will need an attorney to process the adoptions so start shopping around for one now.