Do I need legal representative to have my husband adopt my daughter that is almost 18 years old? And do I need the biological father to sign his rights away where she is almost 18 and he has abandoned her for over 10 years?

Yes, you will need to notify the bio father and get his permission, it may be possible to do it without, but a lot harder and assume that bio father does not respond and enver shows up in court. But even then it is up to judge,