When can baby start solids?

Hello mummies! At what month can my baby start solids? He's 5 months old and already sprouting his first teeny weeny tooth. He will stare at us eating and drooling 😂 but he can't sit yet and has not turn/roll over. He's also been refusing milk but will drink bm in bottle w/o the cap and teat (like a sippy cup). He's always excited drinking his milk like that. Nurse said he can start solid at 6 mths old though just wondering if anyone starts early?