Hey....
You dont say where you got your 'new addition' from and that can have a big impact on how he/she is behaving with you,...i know its a old cliche but its a case of time,paitence and love.
Your new baby is more than likely overwhelmed at the moment and trying to work his/hers new enviroment out,all you can do is be postitive with them and i personally would not force them to interact with you if they show no desire,however i would try to show him/her it could be fun to come to me,ie try showing a toy and simulate play,or when you go out to your yard/garden shout them to come along,slowly they will learn to accept and more importantly trust you and then you have cracked it !