If your baby is in his first month of weaning, have him eat twice a day. But your baby's main source of nutrition is your breast milk, so move at your baby's pace. Don't worry if he doesn't eat very much at this point.
Your baby's expressions have become rich and varied, and he is starting to experiment with his voice, saying "ah, ah, ah." This is called canonical babbling. Some babies at this age can even sit up by themselves. Your baby's fingers and hands will become dexterous, and he will try to put everything he can into his mouth. Place any dangerous items or choke hazards out of his reach.
When you place his favorite toy away from him, he will search for it. Some babies at this time cry at night. This is because your baby's emotions and knowledge have developed. This will no doubt be difficult on you, but you will get through it if you work together with your partner and get enough rest through such methods as taking naps with your baby.