Activities for baby

my lo is coming to 3months. I'm not sure what is expected from my baby. is she suppose to be able to hold her head steadily when doing tummy time on bed/my chest? bc as of now, she cant do it on bed (maybe is soft) but she does relatively well on my chest! sometimes i put her in a sitting position while holding her from her armpits and her head is somewhat stead! is it on the right track? i also talk to my baby and she most of the times respond with coos n ahhs. she also tends to play with her saliva making bubbles. what should i be doing with my baby to get her develop well? am i suppose to read her story books? what kind of toys to get her as well?