You can say "Primer grado es dulce" in Spanish. This phrase captures the idea that first grade is sweet or enjoyable.
So sweet. = Tan dulce.
eres dulce
ricura
muy dulce
Ella es dulce.
frijoles dulces.
dulces sueños
There is not exact Spanish equivalent of this. You could say"Mi amorcito" or "Mi corazoncito"
te quiero (Spanish) -> I love you (English)
hola muchacha dulce
mujer/esposa dulce
Translation: algo dulce