in my bag i have two books
"Tengo dos clases" means "I have two classes" in English.
"Tengo dos" means "I have two."
i have 42 years
I am 32 years old.
I have two rubbers/erasers.
dos libros
To say I have a sister and two brothers in Spanish, you would say: Tengo una hermana y dos hermanos
the spanish translation for 'i have 3 sisters' is: 'Yo tengo tres hermanas'
I have two oranges
Si tengo mascotas yo tengo tres gatos y dos perros.
Tengo dos hermosos hijos (if they're mixed gender or both sons) Tengo dos hermosas hijas (if they're both female)
If you mean 'I am 2 (years old)': 'Tengo dos an~os' - pronounced: TENGaw thoss ANNyoss ('th' as in 'the')