What should my two month old be doing?

My one month old is holding her head up and and can turn it from side to side to get comfortable while sleeping cuz i let her sleep on her tummy it is the only way she will stay asleep longer than 30 minutes she also holds and moves her head to her paci if it is laying next to her. she will smile in response to mine and she will coo and screech in delight while playing on one of those mat thing that have toys above her head that move. she also sticks her tongue out if you stick your tongue out at her.