1 She was right joyous of her just request,

right joyous of > very delighted by just > righteous; proper

2 And, taking by the hand that Faery's son, 3 Gan him instruct in every good behest

Gan > Did; began to behest > injunction (esp. of a religious nature)

4 Of love and righteousness, and well to do,

well > good

5 And wrath and hatred warely to shun,

warely > vigilantly, cautiously

6 That drew on men God's hatred, and His wrath, 7 And many souls in dolours had fordone:

dolours > sorrows, griefs fordone > utterly ruined