Yes, normal. You can encourage your baby while talking to her. Making funny faces, singing songs like nurse ryhmes, making silly sounds, playing peek-a-boo, etc. Smiling and making sounds means your baby is on her track. Just give her some time😊. But if she is showing no signs of laughing by 6 months, seek for your paediatrician.
Normal. But you need to learn more on baby language. Search at TT or YT