You can change your child's name by filling a petition in the family court of the county you reside in for a name change of a child.
Answer Applies to: Texas
First of all this seems to be a little premature the child is only a month old. Second, how does she have his last name sounds like it is not on the birth certificate so whats the issue just call her by your last name. If it is on the certificate he has already admitted paternity. As far as custody and placement file motions with the family court.
Answer Applies to: Rhode Island
To obtain sole custody of a child you will need to petition the court to establish paternity and fix custody provisions. Until you have a court order that says otherwise, both you and the father have equal custody rights of the child. Idaho is by default a joint custody state and it is difficult to obtain sole custody of a child unless there are specific reasons for the sole custody (i.e. domestic violence, abuse, drug/alcohol issues, incarceration, etc.).
Answer Applies to: Idaho
Probably by and through a motion filed with the Family Court.
Answer Applies to: Rhode Island
To get sole custody of her, you would have to file suit and ask for it. Sole custody is seldom awarded unless the other parent is a drug addict or child abuser.
Answer Applies to: Louisiana
You need to file a paternity action with the court.... and you can actually request a name change... some family law judges are reluctant to do that, but I have had the request approved.
Answer Applies to: Arizona
Until he signs the paternity affidavit, he has no rights as the Father. However, be warned, if you ever request any kind of public assistance from the State, the state automatically will seek to establish a child support order and serve him the necessary papers to establish paternity. Once that happens, he can file a Petition to establish a residential schedule to set up visitation with the child. In Wa. state, there is no such thing as "sole custody". A biologlcal Father has a right to visit his child once paternity has been established.
Answer Applies to: Washington
If he is listed as the father on the birth certificate it will be difficult. If he is not listed then you are by default the sole parent, unless he files for paternity.
Answer Applies to: Utah
In order to change the last name of your child you or an attorney would have to file a petition with the court. Obviously, her father would have the right to be given notice of the filing and an opportunity to object. It would be a judge's decision from there. As far as custody, there are two kinds: Legal custody and physical custody. Legal custody gives you the ability to make important decisions yourself regarding things like medical treatment or school attendance, etc. Physical custody deals with where your child will live for the most part. It sounds like you want both sole legal custody and sole physical custody. Unless he agrees to this, you or an attorney would have to file a motion with the court and prove several factors to convince a judge to rule in your favor. Either way, you would want a judgement filed with the court saying who has what rights and obligations, which should also include parenting time and child support. This would help prevent issues from arising in the future.
Answer Applies to: Michigan
As for the issue of custody. I would file a complaint and a temporary motion for custody of your daughter. Based upon the little bit of information you provided, you have a good chance of obtaining primary physical custody. The father does have a right to visit your daughter. But, the filing of the complaint and temporary motion should include a request for child support. The Family Court has a self-help service. I would recommend hiring an attorney.
Answer Applies to: Nevada