I will go.

When describing the future, in English , " will " is used in a sentense.
In Japanese " darou " is attached to the verb with no verb conjugation.

iku : go
iku darou : will go
e/ni : to
gakkou : school
ashita : tomorrow

Watashi wa ashita gakkou ni iku darou. : I , tomorrow, school to , go , will,: I will go to the school tomorrow.

Review the verb conjugation

6basic patterns
-nai : not
-masu : (polite)
-:(plain)
-toki : when
-eba : if
-e/o : (imperativ)

And other patterns categorised by tense

-ta : (past)
- : (plain, present)
- darou :(future, no verb conjugation)

utau : sing
uta: song

Watashi wa uta o utau : I, song, sing ,: I sing a song.
Watashi wa uta o utatta: I , song, sang : I sang a song.
Watashi wa uta o utau darou : I, song, sing, will : I will sing a song.

hanasu : speak

Watashi wa hanasu. : I, speak, : I speak.
Watashi wa hanashita : I , spoke : I spoke.
Watashi wa hanasu darou : I, speak, will : I will speak.

You already know all the Japanese verb patterns.

Don't hesitate to make mistakes, and try to make Japanese sentenses.